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Knowledgebase
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INTRODUCTION
This article discusses the "STAND S HAS N FRAGMENTS" messages that may
appear in e_rror log_ or _system log_ files. These messages can appear
at different log levels (Notice, Warning, Error, Critical, Alert, and
Emergency) [http://docs.markl...
SUMMARY
Occasionally, you might see an "Invalid Database Online Event" error
in your MarkLogic Server Error Log. This article will help explain
what this error means, as well as provide some ways to resolve it.
WHAT THE ERROR MEANS
The XDMP-INVDATABAS...
Details:
Upon boot of CentOS 6.3, MarkLogic users may encounter the following
warning: :WARNING: at fs/hugetlbfs/inode.c:951
hugetlb_file_setup+0x227/0x250() (Not tainted)
MarkLogic 6.0 and earlier have not been certified to run on CentOS
6.3. Th...
INTRODUCTION
Some customers have reported seeing kernel level messages like this in
their _/var/log/messages_ file:
Jan 31 17:41:46 ml-c1-u3 kernel: [17467686.201893] TCP: Possible SYN
flooding on port 7999. Sending cookie
This may also be seen as par...
INTRODUCTION
This article will show you how to add a Fast Data Directory (FDD) to
an existing forest.
DETAILS
The fast data directory stores transaction journals and stands. When
the directory becomes full, larger stands will be merged into the data...
INTRODUCTION
Marklogic has shipped with a ReST API since MarkLogic 7.
In MarkLogic 8 the ReST API was vastly expanded, allowing ways for
MarkLogic Database administrators to manage almost all common
MarkLogic administration tasks over an HTTP connectio...
SUMMARY
On Internet Explorer 9 and Internet Explorer 10, application services
UI should be run in Compatibility Mode.
DETAILS:
When using the Application Services UI in Internet Explorer 9 or
Internet Explorer 10, you may notice some minor UI bugs...
INTRODUCTION
A question that customers frequently ask is for advice on managing
backups outside the standard XQuery APIs
[https://docs.marklogic.com/admin/database] or the web interface
[https://docs.marklogic.com/guide/admin/backup_restore#id_51602]
pro...
SUMMARY
Customers using the MarkLogic AWS Cloud Formation Templates may
encounter a situation where someone has deleted an EBS volume that
stored MarkLogic data (mounted at /var/opt/MarkLogic). Because the
volume, and the associated data are no longer av...
BACKUP/RESTORE SETTINGS FOR LOCAL DISK FAILOVER
When configuring backups for a database, the 'include replica forests'
setting is important in order to handle forest failover events. When
'include replica forests' is set to 'true', both the master and th...
Before executing significant operational procedures on production
systems, such as
* Production Go Live events;
* Major version Upgrades;
* Adding/removing nodes to a cluster;
* Deploying a new application or an application upgrade;
* ...
Mark...
SUMMARY
In some cases it is required to change the default environment
variables of a MarkLogic Server installation or configuration which
are predefined in /etc/sysconfig/MarkLogic
RECOMMENDATION
The standard MarkLogic installation includes a file th...
BEST PRACTICE FOR ADDING AN INDEX IN PRODUCTION
SUMMARY
It is sometimes necessary to remove or add an index to your production
cluster. For a large database with more than a few GB of content, the
resulting workload from reindexing your database can be ...
SUMMARY
MarkLogic Server can ingest and query all sorts of data such as XML,
text, JSON, binary, generic, etc. There are some things to consider
when choosing to simply load data "as-is" vs. doing some degree of
data modeling or data transformation prior...
BEST PRACTICES FOR EXPORTING AND IMPORTING DATA IN BULK
Handling large amounts of data can be expensive in terms of both
computing resources and runtime. It can also sometimes result in
application errors or partial execution. In general, if you're deal...
INTRODUCTION
MarkLogic Server delivers performance at scale, whether we're talking
about large amounts of data, users, or parallel requests. However,
people do run into performance issues from time to time. Most of those
performance issues can be found a...
INTRODUCTION
While there are many different ways to define schemas in MarkLogic
Server, one should be aware of both the location strategy the server
will use (defined here: http://docs.marklogic.com/guide/admin/schemas
[http://docs.marklogic.com/guide/ad...
SUMMARY
Although not exhaustive, this article lists some best practices for
the use of MarkLogic Server and Amazon's VPC
DETAILS
* Nodes within a MarkLogic cluster need to communicate with one
another directly, without the presence of a load balancer...
INTRODUCTION
Problems can occur when trying to explicitly search (or not search)
parts of documents when using a global configuration approach to
include and exclude elements.
GLOBAL APPROACH
Including and excluding elements in a document using a glob...
INTRODUCTION
Backing up multiple databases simultaneously may make some of the
backups fail with error XDMP-FORESTOPIN.
DETAILS
While configuring a scheduled backup, one can also select to backup
the associated auxiliary databases like security, schem...
INTRODUCTION
In MarkLogic 8, support for native JSON and server side JAVASCRIPT was
introduced. We discuss how this affects the support for XML and XQUERY
in MarkLogic 8.
DETAILS
In MarkLogic 8, you can absolutely use _XML_ and _XQuery. XML_ and
_XQue...
INTRODUCTION
Sometimes you may find that there are one or more tasks that are
taking too long to complete or are hogging too many server resources,
and you would like to remove them from the Task Server. This article
presents a way to cancel active ta...
SUMMARY
MarkLogic stores all signed Certificates, private keys, and
Certificate Authority Certificates inside the Security Database. The
Security Database also stores Users, Passwords, Roles, Privileges, and
many other Authentication related configuratio...
SUMMARY
Each node in MarkLogic Server Cluster has a hostname, a human-readable
nickname corresponding to the network address of the device. MarkLogic
retrieves the hostname from underlying operating system during
installation. On Linux, we can retrieve p...
INTRODUCTION: WHEN YOU MAY NEED TO CHANGE THE STATE OF FORESTS
In most cases, all forests in your MarkLogic cluster will be
configured to allow all (any) updates to be made.
If we consider running the following example in Query Console:
In the majori...
INTRODUCTION
This article discusses some of the issues you should think about when
preparing to change the IP address' of a MarkLogic Server.
DETAIL:
If the hostnames stay the same, then changing IP addresses should not
have any adverse side effe...
INTRODUCTION
If you have an existing MarkLogic Server instance running on EC2,
there may be circumstances where you need to change the size of
available storage.
This article discusses approaches to ensure a safe increase in the
amount of available sto...
INTRODUCTION
A common use case in many business applications is to find if an
element exists in any document or not. This article provide ways to
find such documents and explain points that should be taken care of
while designing a solution.
SOLUTION ...
INTRODUCTION
MarkLogic Server has shipped with full support for the W3C XML Schema
[https://www.w3.org/XML/Schema] specification and schema validation
capabilities since version 4.1 (released in 2009).
These features allow for the validation of complet...
SUMMARY
XDMP-ODBCRCVMSGTOOBIG can occur when a non-ODBC process attempts to
connect to an ODBC application server. A couple of reasons that this
can happen is that there is an http application that has been
accidentally configured to point to the ODBC po...
SUMMARY
In MarkLogic Server V7.0-2, the tokenizer keys
[http://docs.marklogic.com/guide/search-dev/languages#id_59632], for
languages where MarkLogic provides generic language support
[http://docs.marklogic.com/guide/search-dev/languages#id_40354], were
...
INTRODUCTION
This Knowledgebase article outlines the procedure to enable HTTPS on
an AWS Elastic Load Balancer (ELB) using Route 53 or an external
supplier as the DNS provider and with an AWS generated certificate.
The AWS Certificate Manager (ACM) aut...
INTRODUCTION
HAProxy (http://www.haproxy.org/ [http://www.haproxy.org/]) is a free,
fast and reliable solution offering high availability, load balancing
and proxying for TCP and HTTP-based applications.
MarkLogic 8 (8.0-8 _and above_) and MarkLogic 9 ...
SUMMARY
MarkLogic Server organizes TRUSTED CERTIFICATE AUTHORITIES (CA) by
Organization Name. Trusted Certificate Authorities are the issuers of
digital certificates, which in turn are used to certify the public key
on behalf of the named subject as give...
INTRODUCTION
MarkLogic Server is engineered to scale out horizontally by easily
adding forests and nodes. Be aware, however, that when adding
resources horizontally, you may also be introducing additional demand
on the underlying resources.
DETAILS
On...
SUMMARY
MarkLogic Application Servers will keep a connection open after
completing and responding to a request, waiting for another new
request, until the _Keep Alive_ timeout expires. However, there is an
exception scenario where the connection will clo...
SUMMARY
CSV files are a very common data exchange format. It is often used as
an export format for spreadsheets, databases or any other application.
Depending on the application, you might be able to change the
delimiter character to a #hash or *aster...
INTRODUCTION:
MarkLogic Server allows you to set-up an alerting application to
notify users when new content is available that matches a predefined
query. This can be achieved through the Alerting API with the Content
Processing Framework (CPF).
[http://...
INTRODUCTION
If you're looking at the MarkLogic Admin UI on port 8001, you may have
noticed that the status page for a given database displays the last
backup dateTime for a given database.
We have been asked in the past how this gets computed so the s...
PROBLEM:
When searching for matches using OR'ed word-queries, and in the case
where there are overlapping matches, (i.e. one query contains the text
of another query), the results of a cts:highlight query are not as
desired.
For example:
let $p :=
...
INTRODUCTION
In the Scalability, Availabilty & Failover Guide
[http://docs.marklogic.com/guide/cluster], the node communication
section [http://docs.marklogic.com/guide/cluster/clustering#id_87995]
describes a quorum
[https://help.marklogic.com/Knowledge...
SUMMARY
This article discusses what happens when you backup or restore your
database after a local disk failover event on one of the database
forests.
INTRODUCTION
MarkLogic Server provides high availability in the event of a data
node failure. Da...
INTRODUCTION
_From the documentation:_
Queries on a Replica database must run at a timestamp that lags the
current cluster commit timestamp due to replication lag. Each forest
in a Replica database maintains a special timestamp, called a
Non-blocki...
INTRODUCTION
Database Replication replicates fragments/documents from a source
database to a target database. You may see different database sizes
(even when active fragment counts are then same) between Master and
Replica Databases. This article provide...
INTRODUCTION
If your MarkLogic Server has it's logging level set to "Debug", it's
common to see a chain of _'Detecting'_ and _'Detected'_ messages that
look like this in your ErrorLogs:
2015-01-27 11:11:04.407 Debug: Detected indexes for database
Docum...
SUMMARY
This article will provide steps to debug applications using the
Alerting API that are not triggering an alert.
DETAILS
1) Check that all required components are present in the database
where alerting is setup: config, actions, rules. Run the...
INTRODUCTION
Division operations involving integer or long datatypes may generate
XDMP-DECOVRFLW in MarkLogic 7. This is the expected behavior but it
may not be obvious upon initial inspection.
For example, similar queries with similar but different i...
CONTEXT:
There are options 'maintain last modified' and 'maintain directory
last modified' on the Admin UI for a database, which when turned on
add properties to every document inserted in the database. There may
be a need to remove all the property fra...
INTRODUCTION
This KB article lists some available tools for continuous integration
and automatically deploying the MarkLogic Server
DEPLOYMENT
_Roxy_ is an open source utility for configuring and deploying
MarkLogic applications. Using Roxy you can de...
SUMMARY
This article will help MarkLogic Administrators to monitor the health
of their MarkLogic cluster. By studying the attached scripts, you will
learn how to find out which hosts are down and which forests have
failed over, enabling you to take the n...
SUMMARY:
After adding or removing a forest and correspond replica forest in a
database, we have seen instances where the Rebalancer does not
properly distribute the documents amongst existing and newly added
forests.
For this particular instance, XDMP...
Search fundamentals
Difference between _CTS:CONTAINS AND FN:CONTAINS_
1) fn:contains is a substring match, where as cts:contains performs
query matching
2) cts:contains therefore can utilize general queries and stemming,
where fn:contains does not...
INTRODUCTION
MarkLogic Server provides a variety of disaster recovery (DR)
facilities including full backup, incremental backup, and journal
archiving that when combined with other ML features can create a
complete disaster recovery strategy. This paper...
INTRODUCTION
In the more recent versions of MarkLogic Server, there are checks in
place to prevent the loading of invalid documents (such as documents
with multiple root nodes). However, documents loaded in earlier
versions of MarkLogic Server can now re...
INTRODUCTION
This article talks about effects of case sensitivity of search term on
search score and thus on final order of search results for a secondary
query which is using cts:boost-query and weight. The case-insensitive
word term is treated as the ...
BACKGROUND
MarkLogic Server includes element level security (ELS), an addition to
the security model that allows you to specify security rules on
specific elements within documents. Using ELS, parts of a document may
be concealed from users who do not ha...
INTRODUCTION
Some customers have reported problems when attempting to access the
Configuration Manager
[http://docs.marklogic.com/guide/admin/config_manager#chapter]application.
In the past, this has been attributed to part of the upgrade process
failing...
SUMMARY
Does MarkLogic provide encryption at rest?
MARKLOGIC 9
MarkLogic 9 introduces the ability to encrypt 'data at rest' - data
that is on media (on disk or in the cloud), as opposed to data that is
being used in a process. Encryption can be applie...
INTRODUCTION
Here we compare XDBC servers and the Enhanced HTTP server in MarkLogic
8.
DETAILS
XDBC servers are still fully supported in MarkLogic Server version 8.
You can upgrade existing XDBC servers without making any changes and
you can create ne...
INTRODUCTION
This article talks about best practices for use of external proxies vs
using rewriter rules in the Enhanced HTTP server.
DETAILS
Whether to use external proxies versus using rewriter rules in the
Enhanced HTTP application server is an app...
SUMMARY
A forest reindex timeout error may occur when there are transactions
holding update locks on documents for an extended period of time. A
reindexer process is started as a result of a database index change or
a major MarkLogic Server upgrade. T...
INTRODUCTION
Users of Java based batch processing applications, such as CoRB,
XQSync, mlcp and the hadoop connector may have seen an error message
containing "PREMATURE EOF, PARTIAL HEADER LINE READ". Depending on how
exceptions are managed, this may cau...
SUMMARY
Here we discuss various methods for sharing metering data with
Support: telemetry in MarkLogic 9 and exporting monitoring data.
DISCUSSION
TELEMETRY
In MARKLOGIC 9, enabling telemetry collects, encrypts, packages, and
sends diagnostic and sys...
INTRODUCTION
To avoid index bloat, MarkLogic only records positions in its indexes
for words once for word-query fields
[http://docs.marklogic.com/guide/admin/wordquery#chapter]. When word
positions are necessary to accurately match element-word queries,...
INTRODUCTION
A "fast data directory
[http://docs.marklogic.com/guide/performance/disk-storage#id_17115]"
is configurable for each forest, and can be set to a directory built
on a fast file system, such as one using SSDs. Refer to Using a mix of
SSD and ...
INTRODUCTION
The Performance Considerations
[http://docs.marklogic.com/guide/ingestion/performance] section of the
Loading Content Into MarkLogic Server
[http://docs.marklogic.com/guide/ingestion] documentation states
"_When you load content, MarkLogic...
SUMMARY
There are situations where the SVC-DIRREM, SVC-DIROPEN and SVC-FILRD
errors occur on backups to an NFS mounted drive. This article explains
how this condition can occur and describes a number of recommendations
to avoid such errors.
Under norma...
INTRODUCTION
It has long been possible to store binary files in MarkLogic. In the
MarkLogic 5 release in 2011, binary support was enhanced to allow for
even more control over binary files.
The purpose of this Knowledgebase article is not to cover MarkL...
People often want fine-grained entitlement control in the applications
they build on top of MarkLogic Server. This article discusses two
options and their performance implications.
BEST PRACTICE
Often, we'll see people attempt an implementation using M...
SUMMARY
When attempting to start MarkLogic Server on older versions of Linux
(Non-supported platforms), a "Floating Point Exception" may prevent
the server from starting.
Example of the error text from system messages:
kernel: MarkLogic[29472] ...
Introduction
Attached to this article is an XQuery module: "appserver-status.xqy",
which will generate a report on all requests currently "in-flight"
across ALL application servers in your cluster
Usage
Run this in Query Console (be sure to displa...
INTRODUCTION
At the time of this writing (MarkLogic 9), MarkLogic Server cannot
perform spherical queries, as the geospatial indexes do NOT support a
true 3D coordinate system. In situations where cylindrical queries are
sufficient, you can create a 2D ...
INTRODUCTION
The MarkLogic Monitoring History dashboard
(http://localhost:8002/history/ [http://localhost:8002/history/]) is
probably the easiest way to gather monitoring history data, but almost
all of this information available within the monitoring da...
Introduction
When configuring database replication, it is important to note that
the _Connect Forests by Name_ field is true by default. This works
great because, when new forests of the same name are later added to
the Master and Replica databases, t...
MARKLOGIC DEFAULT GROUP LEVEL CACHE AND HUGE PAGES SETTINGS
The table below shows the default (and recommended) group level cache
settings based on a few common RAM configurations for the 9.0-9.1
release of MarkLogic Server:
TOTAL RAM
LIST CACHE
...
Introduction
MarkLogic Server has a notion of groups, which are sets of similarly
configured hosts within a cluster.
Application servers (and their respective ports) are scoped to their
parent group.
Therefore, you need to make sure that the hos...
PROBLEM:
The errors 'XDMP-MODNOTFOUND - Module not found' and 'XDMP-NOPROGRAM -
Server unable to build program from request' may occur when the
requested XQuery document does not exist or the user does not have the
right permissions on the module.
SOL...
INTRODUCTION
Recent exploits in the TLS protocol such as POODLE, FREAK, LogJam, and
SLOTH have rendered TLSv1.0 and SSLv3 largely obsolete. Additionally,
standards councils such as PCI (Payment Card Industry) and NIST
(National Institute of Standards & T...
Introduction: Getting More Information About The Bugs Fixed Between
Releases
As a general recommendation, we encourage customers to keep the
server up-to-date with patch releases at any case.
If you would like a list of some of the published bugs tha...
INTRODUCTION
In Amazon Web Services, AMIs have unique ids based on their region.
There will be many cases when you want to use multiple regions (for
example: maintenance of two clusters in separate geographical
regions). Below is an example of how to fin...
SUMMARY
MarkLogic Server has several different features that can help manage
data across multiple database instances. Those features differ from
each other in several important ways - this article will focus on
high-level distinctions and will provide po...
INTRODUCTION
Upgrading individual MarkLogic instances and clusters is generally
very easy to do and in most cases requires very little downtime. In
most cases, shutting down the MarkLogic instance on each host in turn,
uninstalling the current release, i...
INTRODUCTION
spell:suggest() and spell:suggest-detailed aren't simply looking for
character differences between the provided strings and the strings in
your dictionaries - they're also factoring in differences in the
resulting phonetics represented by...
BACKGROUND
A database consists of one or more forests. A forest is a collection
of documents (mostly XML trees, thus the name), implemented as a
physical directory on disk. Each forest holds a set of documents and
all their indexes.
When a new d...
Summary
The following article explains the way in-memory caches are used by
MarkLogic Server and how can they be utilized to improve query
execution.
DETAIL
MarkLogic Server provides several caches that are used to improve the
performance during quer...
INTRODUCTION
This Knowledgebase article is a general guideline for backups using
the journal archiving feature for both free space requirements and
expected file sizes written to the archive journaling repository when
archive journaling is enabled and ac...
INTRODUCTION
Content processing applications often require multi-step processing.
Each step in the process performs a particular task or set of tasks.
The Content Processing Framework in MarkLogic Server supports these
types of multi-step conversion pro...
INTRODUCTION
Sometimes, when a host is removed from a cluster in an improper manner
-- e.g., by some means other than the Admin UI or Admin API, a remote
host can still try to communicate with its old cluster, but the
cluster will recognize it as a "for...
Introduction
Sometimes, when a cluster is under heavy load, your cluster may show
a lot of XDQP-TIMEOUT messages in the error log. Often, a subset of
hosts in the cluster may become so busy that the forests they host get
unmounted and remounted repeat...
INTRODUCTION
Under normal operations, only a single user object is created for a
user-name. However, when users are migrated from another security
database and if the recommend checking
[https://help.marklogic.com/Knowledgebase/Article/View/192/0/restori...
INTRODUCTION
For hosts that don't use a standard US locale (_en_US_) there are
instances where some lower level calls will return data that cannot be
parsed by MarkLogic Server. An example of this is shown with a host
configured with a different locale w...
SUMMARY
This Knowledgebase article outlines the necessary steps required in
importing an existing (pre-signed) Certificate into MarkLogic Server
and configuring a MarkLogic Application Server to utilize that
certificate.
EXISTING (PRE-SIGNED) CERTIFICA...
INTRODUCTION
This article discusses the effects of the incremental backup
implementation on Recovery Point Objectives (RPO) and Recovery Time
Objectives (RTO).
DETAILS
With MarkLogic 8 you can have multiple daily incremental backups with
minimal impac...
SUMMARY
MarkLogic Admin GUI is convenient place to deploy the Normal
Certificate infrastructure or use the Temporary Certificate generated
by MarkLogic. However for certain advance solutions/deployment we need
XQuery based admin operations to configure M...
INTRODUCTION
Okta [https://www.okta.com] provides secure identity management and
single sign-on to any application, whether in the cloud, on-premises
or on a mobile device.
The following procedure describes the procedure required to integrate
MarkLogic...
INTRODUCTION
MarkLogic server provides pre-commit or post-commit triggers and these
triggers listens for certain events to occur and then invokes a
configured XQuery module to run after event occurs. It is a common use
case to create a common function in...
INTRODUCTION
We are always looking for ways to understand and address performance
issues within the product and we are addressing this by adding the
following new diagnostic features to the product.
NEW TRACE EVENTS IN MARKLOGIC SERVER
Some new diagno...
SUMMARY
The jemalloc library is included with the MarkLogic install and is
recommended to use as it has shown a performance boost over the
default Linux malloc library. It is included with the MarkLogic server
install and is configured to be used by def...
INTRODUCTION
This article compares JSON support in MarkLogic Server versions 6, 7,
and 8, and the upgrade path for JSON in the database.
HOW IS NATIVE JSON DIFFERENT THAN THE PREVIOUS JSON SUPPORT?
Previous versions of MarkLogic Server provided XQuery...
INTRODUCTION
MarkLogic Server provides a couple of useful techniques for keeping
values in memory or resolving values without having to scan for
documents on-disk.
OPTIONS
There are a few options available:
1. CTS:ELEMENT-VALUES performs a lexicon l...
SUMMARY
This article explains how to kill Long Running Query and related
timeout configurations.
PROBLEM SCENARIO
At some point, we've all run into an inefficient long running query.
What should we do if we don't want to wait for the query to complete...
INTRODUCTION
MarkLogic Server allows you to configure MarkLogic Server so that
users are authenticated using an external authentication protocol,
such as Lightweight Directory Access Protocol (LDAP) or Kerberos.
These external agents serve as centralized...
INTRODUCTION: THE ISSUE
MarkLogic performs Nested lookups on the LDAP Groups assigned to a
user to determine which roles the user will be assigned. If the groups
belong to multiple Active Directory Domains within a federated Active
Directory Forest then ...
SUMMARY
A LEAP SECOND [http://en.wikipedia.org/wiki/Leap_second], as defined
by wikipedia is "_a one-second [http://en.wikipedia.org/wiki/Second]
adjustment that is occasionally applied to Coordinated Universal Time
[http://en.wikipedia.org/wiki/Coordina...
SUMMARY
The internal mechanisms MarkLogic Server uses to implement security
are query constraints. Lexicon search performance may be impacted by
security query contraints. If performed with admin credentials,
Lexicon searches will not be impacted by t...
For MarkLogic Server v6.0, the absolute maximum number of MarkLogic
Servers in a Cluster is 256, but the optimum is around 64.
SUMMARY
MarkLogic recommends the default "ordered" option for Linux EXT3 and
EXT4 file-systems.
File System administrators in Linux are tempted to use the
data=writeback option to achieve higher throughput from their
file-system, but this comes with th...
INTRODUCTION
Here we discuss management of temporal documents.
DETAILS
In MarkLogic, a temporal document is managed as a series of versioned
documents in a protected collection. The 'original' document inserted
into the database is kept and never chan...
INTRODUCTION
When CPF is installed, a number of new documents are created for the
nominated TRIGGERS database associated with that database.
This Knowledgebase article is designed to show you what CPF creates on
install, in the event that you want to s...
INTRODUCTION
If you have an existing MarkLogic Server cluster running on EC2, there
may be circumstances where you need to upgrade the existing AMI with
the latest MarkLogic rpm available. You can also add a custom OS
configuration.
This article assum...
INTRODUCTION
A powerful new feature was added to MarkLogic 8 - the ability to build
applications around a declarative HTTP rewriter
[http://help.marklogic.com//docs.marklogic.com/guide/app-dev/XMLrewriter].
You can read more about MarkLogic Server's HTTP...
INTRODUCTION
Prior to the 9.0-9 release, MarkLogic currently provides support for
the Oracle JDK 8
[https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html].
However, Oracle have recently announced End of Public Updates of Ja...
SUMMARY
The default configuration of MarkLogic Application Servers are NOT
vulnerable to the FREAK SSL attack.
WHAT IS THE FREAK SSL ATTACK?
Tuesday 2015/03/03 - Researchers of miTLS team (joint project between
Inria and Microsoft Research) disclosed ...
SUMMARY
MarkLogic 9 introduces Certificate based User Authentication, which
allows users to Log into MarkLogic Server without being required to
enter user name/password. In previous versions, Certificates were only
utilized to restrict client access to ...
SUMMARY
MarkLogic 9 introduces Certificate based User Authentication, which
allows users to Log into MarkLogic Server without being required to
enter user name/password. In previous versions, Certificates were only
utilized to restrict client access to M...
SUMMARY
MarkLogic may fail to start, with an XDMP-ENCODING error,
_Initialization: XDMP-ENCODING: (err:XQST0087) Unsupported character
encoding: ascii. _This is caused by a mismatch in the Linux Locale
character set, and the UTF-8 character set required ...
INTRODUCTION
There is a lot of useful information in MarkLogic Server's
documentation surrounding many of the new features of MarkLogic 9 -
including the new SQL implementation, improvements made to the ODBC
driver and the new system for generating SQL "...
INTRODUCTION
This article details changes to the upgrade procedures for MarkLogic 9
AMIs.
MarkLogic 9 now supports 1-click deployment in AWS Marketplace. This
is an addition to existing options of manual launch of an AMI and
launching MarkLogic cluster...
INTRODUCTION: THE DECIMAL TYPE
In order to be compliant with the XQuery specification and to satisfy
the needs of customers working with financial data, MarkLogic Server
implements a decimal type, available in XQuery and server-side
JavaScript.
Decimal...
SUMMARY
A database or forest backup in MarkLogic Server may be significantly
slower than just performing a file copy (cp in Linux). Why is this so?
DETAILS
Using CP on very large files on a large-memory linux can produce huge
amounts of dirty page...
INTRODUCTION
MarkLogic automatically provides
* ANSI REPEATABLE READ level of isolation for update transactions,
and
* Serializable isolation for read-only (query) transactions.
MarkLogic can be made to provide ANSI SERIALIZABLE isolation for
upd...
SUMMARY
Text is stored in MarkLogic Server in Unicode NFC normalized form.
DISCUSSION
In MarkLogic Server, all text is converted into Unicode NFC normalized
form before tokenization and storage.
Unicode considers NFC-compatible characters to be esse...
ABSTRACT
In MARKLOGIC SERVER VERSION 9, the default tokenization and stemming
code has been changed for all languages (except English tokenization).
Some tokenization and stemming behavior will change between
MARKLOGIC 8 and MARKLOGIC 9. We expect that, ...
WHAT IS MARKLOGIC DATA HUB?
MarkLogic's Data Hub increases data integration agility, in contrast
to time consuming upfront data modeling and ETL. Grouping all of an
entity's data into one consolidated record with that data's context
and history, a MarkL...
SUMMARY
In addition to the multiple language support in MarkLogic Server,
MarkLogic Server also supports ISO codes listed below for
representation of names for these languages.
MARKLOGIC SUPPORTED ISO CODES
MarkLogic supports following ISO codes for...
SUMMARY
There are many different kinds of locks present in MarkLogic Server.
Transaction locks are obtained when MarkLogic Server detects the
potential of a transaction to change the database, at which point the
server considers it to be an update tran...
With the release of MarkLogic Server versions 8.0-8 and 9.0-4,
detailing memory use broken out by major areas is periodically
recorded to the error log. These diagnostic messages can be useful for
quickly identifying memory resource consumption at a glanc...
INTRODUCTION
The MarkLogic Monitoring History
[http://docs.marklogic.com/guide/monitoring] feature allows you to
capture and view critical performance data from your cluster. By
default, this performance data is stored in the Meters database
[http://doc...
MONITORING HISTORY
The Monitoring History feature allows you to capture and view critical
performance data from your cluster. Monitoring History capture is
enabled at the group level. Once the performance data has been
collected, you can view the data i...
SUMMARY:
Prior to MarkLogic 4.1-5, role-ids were randomly generated. We now
use a hash algothm that ensures that roles created with the same name
will be assigned the same role-id. When attempting to migrate data
from a forest created prior to MarkLog...
INTRODUCTION
Those familiar with versions of MarkLogic Server prior to MarkLogic 7
may have heard the 3X disk space rule being mentioned. At the time of
writing, references to are to be found in the MarkLogic 5
documentation
[http://docs.marklogic.com/5....
SUMMARY
New and updated mimetypes
[http://docs.marklogic.com/admin-help/mimetype] were added for
MARKLOGIC 8. If your _MarkLogic Server_ instance has customized
mimetypes, the upgrade to _MarkLogic Server v8.0-1_ will NOT update
the mimetypes table.
DE...
INTRODUCTION
In this article, we discuss use of xdmp:cache-status in monitoring
cache status, and explain the values returned.
DETAILS
Note that this is a relatively expensive operation, so it's not
something to run every minute, but it may be valuabl...
We do NOT recommend configuring multiple forests for the Security
database, as this can cause failover issues when doing upgrades and
restarts. Security database should have a single primary forest and
replicas on all hosts to ensure High Availability.
SUMMARY
When restarting very large forests, some customers have noted that it
may take a while for them to mount. While the forests are mounting,
the database is unable to come online, thus impacting the availability
of your main site. This article show...
INTRODUCTION
MarkLogic Server's 'DatabaseClient' instance represents a database
connection sharable across threads. The connection is stateless,
except that authentication is done the first time a client interacts
with the database via a Document Manager...
SUMMARY
Clock synchronization plays a critical part in the operation of a
MarkLogic Cluster.
MarkLogic Server expects the system clocks to be synchronized across
all the nodes in a cluster, as well as between Primary and Replica
clusters. The acceptabl...
SUMMARY
On March 1, 2016, a vulnerability in OpenSSL
[http://openssl.org/news/vulnerabilities.html#y2016] named DROWN, a
man-in-the-middle attack that stands for "Decrypting RSA with Obsolete
and Weakened eNcryption", was announced. All MARKLOGIC SERVER ...
INTRODUCTION
Ops Director enables you to monitor MarkLogic clusters ranging from a
single node to large multi-node deployments. A single Ops Director
server can monitor multiple clusters. Ops Director provides a unified
browser-based interface for easy a...
SUMMARY
This article briefly looks at the performance implications of ad hoc
queries versus passing external variables to a query in a module
DETAILS
Programatically, you can achieve similar results by dynamically
generating ad hoc queries on the ...
SUMMARY
MarkLogic does not enforce a programmatic upper limit on How many
indexes you *can* have. This leaves open the question of how many
range indexes should be used in your application. The answer is that
you should have as many as the application re...
PERFORMANCE IMPLICATIONS OF UPDATING MODULE AND SCHEMA DATABASES
This article briefly looks at the performance implications of adding
or modifying modules or schemas to live (production) databases.
DETAILS
When XQuery modules or schemas are referenced...
OVERVIEW
Performance issues in MarkLogic Server typically involve either 1)
UNNECESSARY WAITING ON LOCKS or 2) OVERLARGE WORKLOADS. The goal of
this knowledgebase article is to give a high level overview of both of
these classes of performance issue, as ...
_This article is a snapshot of the talk that Jason Hunter and Franklin
Salonga gave next at MARKLOGIC WORLD 2014, also titled, "Performance
Theory: Tales From The MarkLogic Support Desk." Jason Hunter is Chief
Architect and Frank Salonga is Lead Engineer ...
INTRODUCTION
Administrators can achieve very fine granularity on restores when
incremental backups are used in conjunction with log archiving.
DETAILS
Journal archiving can enable a restore to be performed to any
timestamp since the last incremental b...
SUMMARY
There are index settings that may be problematic if your documents
contain encoded binary data (such as Base64 encoded binary). This
article identifies a couple of these index settings and explains the
potential pitafall.
DETAILS
When WORD...
INTRODUCTION
Looking at the MarkLogic Admin UI, you may have noticed that the
status page for a given database displays the last backup date and
time for a given database. We have been asked in the past how this
gets computed so the same check can be per...
INTRODUCTION
In this Knowledgebase article, we will discuss a technique which will
allow you to scope queries in such a way to ensure that they occur
only within a parent element.
DETAILS
CTS:ELEMENT-QUERY
Consider a scenario where you have an XML do...
SUMMARY
This article explains why you may encounter Cross-Site Request Forgery
(CSRF) error (SECURITY-BADREQUEST) when using MarkLogic Server's Query
Console application and how the issue can be resolved.
DETAILS
Since the 8.0-6 release of MarkLogic S...
SUMMARY
There is a limit to the number of registered queries held in the
forest registry. If your application does not account for that fact,
you may get unexpected results.
WHERE IS IT?
If a specific registered query is not found, then a cts:sea...
SUMMARY
If your index settings have a very large number of range indexes
specified (on the order of thousands or even tens of thousands), you
may find your MarkLogic Server instance returning a message saying
that it "Cannot allocate memory" - even when ...
INTRODUCTION
Seeing too many "stand limit" messages in your logs frequently? This
article explains what this message means to your application and what
actions should you take.
WHAT ARE STANDS AND HOW THEIR NUMBERS CAN INCREASE?
A stand holds a subs...
INTRODUCTION
This article presents the steps to create a Read only Access User and
a full access user to a Webdav Server.
DETAILS
For read-only WebDAV access you can connect to WebDAV using the
credentials of a user who does not have the rights to ins...
OVERVIEW
UPDATE TRANSACTIONS run with _readers/writers locks_, obtaining locks
as needed for documents accessed in the transaction. Because update
transactions only obtain locks as needed, update statements always see
the latest version of a document. Th...
CONTEXT
This KB article talks specifically about how the Rebalancer interacts
with database replication, and how to solve the issues that may arise
if not configured correctly.
For a general discussion on how rebalancing works in MarkLogic, refer
to th...
On a MarkLogic 7 cluster or a MarkLogic 8 cluster that was previously
upgraded from MarkLogic Server version 6, reindexing of the triple
index does not always get triggered when the triple index is turned
off. Reindexing is performed after turning off an ...
SUMMARY
When used as a file system, GFS needs to be tuned for optimal
performance with MarkLogic Server.
RECOMMENDATIONS
Specifically, we recommend tuning the demote_secs and statfs_fast
parameters. The demote_secs parameter determines the amount of t...
INTRODUCTION
MarkLogic is supported on XFS filesystem. The minimum system
requirements can be found here:
https://developer.marklogic.com/products/marklogic-server/requirements-9.0
[https://developer.marklogic.com/products/marklogic-server/requirements...
SUMMARY
The XDMP-LABELBADMAGIC error appears when attempting to mount a forest
with a corrupted or zero length Label file. This article identifies a
potential cause and provides the steps required to work around this
issue.
Details
The XDMP-LABELBADM...
INTRODUCTION
In some situations an existing cluster node needs to be replaced.
There are multiple reasons for this activity like hardware failure or
hardware replacement.
In this Knowledgebase article we will outline the steps necessary to
replace the ...
STEMMING:
MarkLogic Server supports stemming in English and other languages. If
stemmed searches are enabled in the database configuration, MarkLogic
Server automatically searches for words that come from the same stem
of the word specified in the query...
INTRODUCTION
MarkLogic Server offers Fast Data Directories, and Large Data
Directories to allow customers to better utilize their available
infrastructure. This allows an organization to offload large objects
to cheaper storage, or improve performance wi...
This is a procedure to take hosts out of a MarkLogic cluster with
minimal unavailability. It is assumed that High availability is
configured using local disk failover
[http://docs.marklogic.com/guide/cluster/failover#id_65543]and all
master forests have a...
INTRODUCTION
Using MarkLogic Server's Admin UI, it is possible to modify the name
of a single host via Admin UI -> Configure -> Hosts -> 'Select Host in
question' and update the name and click ok.
However, if you would want to change/update the hostnam...
INTRODUCTION
In a multiple node cluster with local disk failover configured, there
may be a need to replace a server with new hardware. This article
explains how to do that while preserving the failover configuration.
SAMPLE CONFIGURATION
Consider a 3...
SUMMARY
A Socket bind error will occur when there are more than two MarkLogic
Server instances running simultaneously in the same host. Two
simultaneous instances of MarkLogic Server might occur if a MarkLogic
Server process did not gracefully shutdown ...
BACKWARDS COMPATIBILITY
Newer versions of MarkLogic will support backups taken from older
versions of the software. This restore may cause a reindex of the data
in order to upgrade the database to the current feature release
version. Information on backi...
INTRODUCTION
When a database backup taken on Cluster A is restored (using
incremental backup) on Cluster B, sometimes it fails with the message
on the admin screen -
THE DATABASE RESTORE HAS FAILED. PLEASE CHECK THE SERVER LOGS FOR
DETAILS.
A quick ...
SUMMARY
When performing a Security database backup on one cluster and
restoring on another cluster, there are precautionary measures to be
taken.
DETAILS
Since MarkLogic Server version 4.1-5, the internal user IDs are
derived from the hash of the us...
SUMMARY
If MarkLogic Server is installed on an Amazon Elastic Compute Cloud
(EC2) instance and you execute queries in the MarkLogic Query Console,
it is possible that the queries will be silently cancelled. Long
running queries may time out because of a...
INTRODUCTION: SUMMARY
When attempting to access files stored on an Amazon AWS S3 Bucket
using MarkLogic an SVC-S3SOCERR error is raised.
CAUSE
Under some conditions when installing a MarkLogic server, such as
unattended scripted installation, some req...
INTRODUCTION
If you have forest level failover configured on your MarkLogic
cluster, in the event that a single host in the cluster loses contact
with the other hosts, the forests will _fail over_ to the backup set
of forests: the replica forests
WHAT ...
SUMMARY
This article explores fragmentation policy decisions for a MarkLogic
database, and how search results may be influenced by your
fragmentation settings.
DISCUSSION
FRAGMENTS VERSUS DOCUMENTS
Consider the below example.
1) Load 20 test docume...
WHAT IS DLS?
The Document Library Service (DLS) enables you to create and maintain
versions of managed documents in MarkLogic Server. Access to managed
documents is controlled using a check-out/check-in model. You must
first check out a managed docu...
SUMMARY
This knowledge base discusses the various aspect of vulnerabilty found
in glibc library (CVE-2015-7547) in respect to MarkLogic Server.
Please note - We do not expect any changes to be done at MarkLogic
Application software level to protect aga...
INTRODUCTION
This article discusses the capabilities of JavaScript and XQuery, and
the use of JSON and XML, in MarkLogic Server, and when to use one vs
the other.
DETAILS
CAN I DO EVERYTHING IN JAVASCRIPT THAT I CAN DO IN XQUERY? AND
VICE-VERSA?
Yes,...
INTRODUCTION
This article discusses how JavaScript is implemented in MarkLogic
Server, and how can modules be reused?
IS NODE.JS EMBEDDED IN THE SERVER?
MarkLogic 8 embeds Google's V8 JavaScript engine
[https://code.google.com/p/v8/], just like Node.j...
INTRODUCTION
The notion of "flipping" back control (from failed-over replica forest
back to the master forest) has been covered in previous Knowledgebase
articles:
https://help.marklogic.com/Knowledgebase/Article/View/427/0/scripting-failover-flipping-...
SUMMARY
Some MarkLogic Server sites are intalled in a 1GB network environment.
At some point, your cluster growth may require an upgrade to 10GB
ethernet. Here are some hints for knowing when to migrate up to 10GB
ethernet, as well as some ways to work a...
INTRODUCTION
The performance and resource consumption of E-nodes is determined by
the kind of queries executed in addtion to the distribution and amount
of data. For example, if there are 4 forests in the cluster and the
query is asking for only the top-...
The recommended way to run MarkLogic on AWS is to use the "managed"
Cloud Formation template provided by MarkLogic:
https://developer.marklogic.com/products/cloud/aws
[https://developer.marklogic.com/products/cloud/aws]
The documentation for it is her...
INTRODUCTION
We discuss why MarkLogic server should be started with root
priviledges.
DETAILS
It is possible to install MarkLogic Server in a directory that does
not require root priviledges.
There's also a section in our Installation Guide (Configu...
SUMMARY
Quorum is used to either evict or keep a node in a cluster but is
quorum requierd even while starting my cluster?
WHAT IS QUORUM?
Each node in a cluster communicates with all of the other nodes in the
cluster at periodic intervals. This peri...
SUMMARY
When attempting to send email from MarkLogic, from Ops Director, Query
Console, or other application, you might encounter one of the
following errors in your MarkLogic Server Error Log, or in the Query
Console results pane.
* ERROR SENDING MAI...
INTRODUCTION
STEMMING is handled differently between a _word-query_ and
_value-query_; a _value-query_ only indexes using basic stemming.
DISCUSSION
A word may have more than one stem. For example,
cts:stem ('placing')
returns
place
placing
To ...
SUMMARY
When an SSL certificate is expired or out of date, it is necessary to
renew the SSL certificates applied to a MarkLogic Application Server.
The following general steps are required to apply an SSL certificate.
* Create a certificate request...
INTRODUCTION
This article will outline a general strategy for distributing a
specific task across every node in a server.
There are situations where you would like to execute queries against a
number of hosts in a cluster - one such example would be to...
INTRODUCTION
This article discusses version differences of temporal documents in
MarkLogic Server.
DETAILS
MarkLogic Server 8 does not storing the "difference" for temporal
documents. Each version of the temporal document is a full document.
At the ...
INTRODUCTION
Interoperation of Temporal support with other MarkLogic features.
FEATURES THAT SUPPORT TEMPORAL COLLECTIONS
MarkLogic's Temporal feature is built-in to the server and is
supported by many of MarkLogic's power features: Search API,
Semant...
INTRODUCTION
How do you find all versions of a temporal document?
DETAILS
In MarkLogic Server, a temporal document is managed as a series of
versioned documents in a protected temporal collection. In addition,
each temporal document added creates anot...
INTRODUCTION
Allen and ISO operators are comparison operators that can be used in
temporal queries.
DETAILS
Both operator sets are used to represent relations between two
intervals. ISO operators are more general and usually can be
represented by a co...
INTRODUCTION
For terms stored in the index, the _position list_ tracks where they
appear within the document. Positions are used to resolve queries
where distance between terms matter (for example near queries where a
term can appear_ n_ words away from ...
INTRODUCTION
Binary documents often have various associated metadata. For example,
an image may have metadata like a timestamp of when and where it was
taken, and so on. MarkLogic Server server offers the ability to
extract this metadata information fro...
TIMEZONE INFORMATION AND MARKLOGIC
SUMMARY
This article discusses the effect of the implicit timezone on
date/time values as indexed and retrieved.
DISCUSSION
TIMEZONE INFORMATION AND INDEXES
Values are stored in the index effectively in UTC, withou...
INTRODUCTION
XQuery modules can be imported from other XQuery modules in MarkLogic
Server. This article describes how modules are resolved in MarkLogic
when they are imported in Xquery.
DETAILS
HOW MODULES ARE IMPORTED IN CODE
Modules can be impor...
SUMMARY
There are a number of options for transferring data between MarkLogic
Server clusters. The best option for your particular circumstances
will depend on your use case.
DETAILS
DATABASE BACKUP AND RESTORE
To transfer the data between two indepe...
PROBLEM STATEMENT
You have an application running on a particular cluster (the source
cluster), devcluster and you wish to port that application to an new
cluster (the target cluster) testcluster. Porting the application can
be divided into two tasks: co...
SUMMARY:
MarkLogic allows the use of SSL certificates to be used when securing
application servers. This article explains some common issues seen
when importing certificates, as well as methods to troubleshoot
problems.
IMPORTING A CERTIFICATE INTO MAR...
SUMMARY
This article is intended to help investigate certain Kerberos External
Authentication issues, since most of the Kerberos Security
authentication requires much more IT involvement, below are few areas
we recommend to investigate before involving ...
INTRODUCTION
With the introduction of Certificate Based Authentication
[https://docs.marklogic.com/guide/security/security-based-auth] in
MarkLogic 9, users can now log into a MarkLogic without entering
user/password credentials.
Configuring a MarkLogi...
SUMMARY
File and semaphore errors (such as SVC-FILREM & SVC-SEMPOST) seen on
MarkLogic Servers running on the Microsoft Windows platform can
sometimes be attributed to Windows file system handling of MarkLogic
Data files.
This article covers a number o...
SUMMARY
There are situations where the XDMP-BACKDIRSPACE error occurs while
backing up a database. This article explains how this condition can
occur and describes a number of strategies to troubleshoot and to
determine root cause.
Under normal operati...
SUMMARY
Sometimes, following a manual merge, a number of deleted fragments --
usually small number -- are left behind after the merge completes. In
a system that is undergoing steady updates, one will observe that the
number of deleted fragments will go ...
INTRODUCTION
In more recent versions of _MarkLogic Server_, "slow background" error
log messages were added to note and help diagnose slowness.
DETAILS
For "Slow background" messages, the system is timing how long it took
to do some named background a...
SUMMARY
MarkLogic server monitoring dashboard provides a way to Monitor Disk
Usage which is a key monitoring metric. Comparing the disk usage shown
on monitoring dashboard with Disk space on filesystem (for example,
using df -h) reveals difference betwe...
INTRODUCTION
On a typical online transactional project it's not uncommon, at the
end of the project to discover when running at scale that simple tasks
unexpectedly take much longer than expected. You're surprised because
your team know how to avoid writ...
INTRODUCTION
To simplify the calculation, the documentation for disk space
requirements section of the MarkLogic Installation guide
[http://docs.marklogic.com/guide/installation/intro#id_11335] states
that starting from MARKLOGIC 8 (and continued in MAR...
VALUE QUERIES
SUMMARY
Here we summarize some characteristics of value queries and compare to
other approaches.
DISCUSSION
CHARACTERISTICS
Punctuation and space tokens are not indexed as words in the universal
index. Therefore, word-queries involving...
INTRODUCTION
Slow journal frame log entries will be logged at WARNING level in your
ErrorLog file and will mention something like this:
> .....journal frame took 28158 ms to journal...
EXAMPLES
2016-11-17 18:38:28.476 Warning: forest Documents JOURNA...
MARKLOGIC SERVER LOGGING: SLOW INFRASTRUCTURE NOTIFICATIONS
INTRODUCTION
As of _MarkLogic Server_ versions 8.0-6.8 and 9.0-3, MarkLogic Server
has added logging to note and help diagnose slowness.
DETAILS
_MarkLogic Server_ makes extensive use of fi...
INTRODUCTION
In the past, we have heard concerns from customers with regard to
exactly how our scoring works. A couple of examples from Stack
Overflow include:
*
http://stackoverflow.com/questions/12953333/marklogic-score-calculation
[http://stackover...
INTRODUCTION
A common problem that is often encountered is when code which
otherwise worked fine in a development environment is deployed to
production and suddenly begin to show apparent signs of performance
degredation. There could be many reasons for ...
INTRODUCTION
MarkLogic Sever sends log messages to both the operating system log
and the MarkLogic Server file log. This server log file is maintained
as a simple text file. You may view/access the log files from the
'Log' tab on the main page of the Ad...
INTRODUCTION
In early 2015, a significant security vulnerability was found in the
glibc package. Glibc is an implementation of the standard C library
and is a core part of all our currently supported Linux distributions.
A code audit was performed by the...
INTRODUCTION
This KnowledgeBase article will cover the use of Journal files by
MarkLogic server. The concept of Journalling is covered in many places
in our documentation [http://docs.marklogic.com/].
The aim of this article is to augment the online do...
INTRODUCTION
Here we will describe how to see in detail the effect of running the
rebalancer, before it is enabled.
ADMIN UI
The Admin UI lets you check the state of the rebalancer, along with an
estimated completion time if running, on the Database S...
WHAT IS TDE?
Template Driven Extraction (TDE) allows you to:
* Define a relational lens over your document data, so you can query
your data using SQL or the Optic API.
* Use templates to define a semantic lens, specifying which values
from a documen...
SUMMARY
Internally, MarkLogic Server maps URIs to hash values. Hash values are
just numbers. For internal operations, numbers are easier to process
and are more performant than strings. We refer the URI hash as a URI
Key.
DETAILS
WHERE WOULD I SEE A U...
SUMMARY
This article describes the errors thrown when decoding URLs and how to
detect invalid characters to avoid the errors
DETAILS
When decoding certain URLs using xdmp:url-decode(), it is possible
that certain characters will cause one of two err...
INTRODUCTION
There are two ways of leveraging SSDs that can be used independently
or simultaneously.
FAST DATA DIRECTORY
In the forest configuration for each forest, you can configure a Fast
Data Directory. The Fast Data Directory is designed for fast...
INTRODUCTION
MarkLogic AppServer supports several authentication methods such as
Basic, Digest, Kerberos, and in more recent years, SAML and
Certificate-based authentication.
The two most common authentication methods are Basic and Digest
authenticatio...
TIERED STORAGE
MarkLogic Server allows you to manage your data at different _tiers_
of storage and computation environments, with the top-most tier
providing the fastest access to your most critical data and the lowest
tier providing the slowest access ...
INTRODUCTION
Database replication can be used to replicate the contents of a
database spanning a cluster to forests on a similarly configured
cluster. The most common use of database replication is to keep two
identical MarkLogic clusters in sync with ea...
INTRODUCTION
This Knowledgebase article demonstrates how you can use the KeyStore
Explorer [http://keystore-explorer.org/] tools to generate a CA ROOT
CERTIFICATE and end-user certificates for use with MarkLogic Server
(for Application Servers which are ...
INTRODUCTION: MARKLOGIC'S SHARED NOTHING ARCHITECTURE
Each node in your cluster maintains:
* Its own set of group level caches;
* A stack of application servers;
* All configuration files to allow it to understand the entire
topology of the clust...
INTRODUCTION
Can MarkLogic Server be used behind a caching proxy such as Squid
[http://www.squid-cache.org/]?
We present some general pointers and tips for setting up Squid
[http://www.squid-cache.org/], and we provide an example of how you
can use Mar...
Introduction
_mlstat_ is a command line tool that monitors various aspects of
MarkLogic Server performance. It is runs on the MarkLogic node itself
and is modeled on the classic Unix tools like vmstat and mpstat. It is
designed to be always on, runnin...
INTRODUCTION
MarkLogic uses the LDAP "_memberOf_" attribute to determine group
membership for authorising access to specific security roles, however
by default, the "memberOf" attribute is not enabled in an OpenLDAP
server. This article will show to ena...
ABSTRACT
perf is a tool that can help analyze the performance of a process on
Linux.
DISCUSSION
Often, pstack is recommended as a way of understanding the behavior of
MarkLogic Server. pstack works by pausing the MarkLogic process and
printing out an ...
INTRODUCTION
In this Knowledgebase article, we will show you how the rebalancer can
be used to migrate data from a filesystem mount to another separate
mount.
This scenario could occur, for example, if you created some forests
and initially did not spe...
INTRODUCTION
Special care may need to be taken when loading documents into
MarkLogic Server where the document URI contains one or more special
characters. In this article, we will walk through a scenario where
exceptions are thrown if such a URI with sp...
INTRODUCTION
A document uniform resource identifier (URI)
[http://en.wikipedia.org/wiki/Uniform_resource_identifier] is a string
[http://en.wikipedia.org/wiki/Character_string_(computer_science)] of
characters [http://en.wikipedia.org/wiki/Character_(com...
INTRODUCTION
MarkLogic Server is a highly scalable, high performance Enterprise
NoSQL database platform. Configuring a MarkLogic cluster to run as
virtual machi...
SUMMARY
In releases 8.0-5.3 and 7.0-6.4, we've added code to detect lagged
operations and log warnings.
FAST QUERY TIMESTAMP
Every forest has a notion of a "fast query timestamp", also sometimes
referred to as a "nonblocking timestamp". This is the ma...
SUMMARY
Customers will sometimes run into strange issues when submitting
requests to a WebDAV application server from HTTP clients.
DETAIL
The purpose of WebDAV application servers in MarkLogic is to support
the additional HTTP methods provided by...
INTRODUCTION
The session timeout in the XDBC Admin UI
[http://docs.marklogic.com/admin-help/xdbc-server] page controls the
timeout of the server session object. This is different from the XCC
client [http://docs.marklogic.com/guide/xcc/intro] session obj...
INTRODUCTION
An issue that has been brought to our attention in the past is one
where a nightly scheduled backup is set up by a System Administrator
and left to diligently work away in the background. Elsewhere, another
team (or System Administrator) per...
SUMMARY
It's a lot easier to think of what a directory is useful for rather
than to state what it is. Directories are a powerful and efficient way
to group documents in a database. While collections are also powerful
and efficient, directories have alway...
INTRODUCTION
XDQP is a MarkLogic internal protocol used for communication between
nodes in a cluster. This protocol version must be the same on all
hosts of the cluster, and XDMP-XDQPVER message is logged if the
versions are not the same.
Example mess...
SUMMARY
MarkLogic Server can ingest and query all sorts of data such as XML,
text, JSON, binary, generic, etc. - and it can do so with both great
speed and scale. This article contains a simple rule of thumb to
determine when you should do some query or ...
MarkLogic Server is designed to scale horizontally, and goes to great
effort to make sure queries can be parallelized independently of one
another. Nevertheless, there are occasions where users will run into
an issue where, when invoked in parallel, so...
INTRODUCTION:
When trying to restore from a backup previously taken, the
XDMP-BACKDIRINUSE error message may sometimes be encountered:
XDMP-BACKDIRINUSE - Backup data directory currently has a backup job
in progress
As described, the most common oc...
INTRODUCTION
It is possible to encounter an XDMP-RIDXTOOBIG error during a database
merge - for example, you may see an error that looks similar to:
XDMP-FORESTNOT: Forest ... not available: XDMP-FORESTERR: Error in
merge of forest ...: XDMP-RIDXTOOBIG...
XDMP:VALUE() VS. XDMP:EVAL():
Both xdmp:value() and xdmp:eval() are used for executing strings of
code dynamically. However, there are fundamental difference between
the two:
* The code in the xdmp:value() is evaluated against the current
context - if...
SUMMARY
Default Inter-node communication within MarkLogic cluster is done by
XDQP (XML Data Query Protocol) on non-secure channel, with the
assumption that all nodes reside within same secure network. However,
you can set the "XDQP SSL enabled"
[http://d...
SUMMARY
MarkLogic uses a proprietary protocol for internal communication
between nodes in a cluster. This article is describes the XML Data
Query Protocol (XDQP) and related configuration settings.
XDQP VERSION:
Each MarkLogic Server release communica...
XML SERIALIZATION AND OUTPUT OPTIONS
XML AS STORED IN MARKLOGIC SERVER
MarkLogic Server starts by parsing and indexing the document contents,
converting the document from serialized XML (what you see in a file)
to a compressed binary fragment representa...
INTRODUCTION
Fields are a great way of restricting what parts of your documents to
search, based on XML element QNames or JSON propertyNames
[https://help.marklogic.com/Knowledgebase/Article/View/106/0/best-practices-when-trying-to-search-or-not-search-p...
SUMMARY
The ampersand is a special character used to denote a predefined
entity reference in a string literal.
XQUERY W3C RECOMMENDATION
Can be found at http://www.w3.org/TR/xquery-30/
[http://www.w3.org/TR/xquery-30/] .
Section 2.4.5 'URI Literals'...
INTRODUCTION
This article discusses the use of XQuery in JavaScript and vice versa.
USING XQUERY IN JAVASCRIPT
A JavaScript module in MarkLogic can also import an XQuery library and
access its functions and variables as if they were JavaScript. If
you...
Introduction
The first time a query is executed, it will take longer to execute
than subsequent runs. This extra time for the first runs become more
pronounced when importing large libraries. Why is this so and is there
anything that we can do to improv...