== About ==
Elasticsearch is a distributed RESTful search engine built for the cloud. See https://www.elastic.co/about I'd like to recommend the intro video <ref>https://www.elastic.co/webinars/getting-started-elasticsearch</ref> but you have to submit an email to view it. (joe@example.com probably works)
== Community ==
There is a Discourse forum at https://discuss.elastic.co/
== Features ==
See [[mw:Help:CirrusSearch]] for help on how to best use the search functionality (including regex searches).
=== Search Tips ===
This wiki supports Elasticsearch features. So, for example, let's say you want to search for 'Ansible' in the wiki, but you know that there is an Ansible page, and you don't want to be taken directly to that page. Instead, you prefer to actually see all the [Special:Search search results for 'Ansible']. Just prefix your search term with the <code>~</code> character. Now when you press enter, you'll go to the search results page with a full listing of results.
}}
== Video ==* [https://vimeo.com/136326424 Building Elasticsearch: From Idea to {code} to Adoption] The back side of a napkin, a pen, and a few beverages are often the ingredients that yield good ideas. Elasticsearch had a different origin. It started with a need for a simple search box for a collection of recipes. '''Shay Banon''', creator of Elasticsearch and CTO at Elastic, shares the history behind pushing the code for his first open source project that led to the creation of Elasticsearch and it�s rapid adoption by users worldwide. -- ''RISE | August 2015''
*[https://vimeo.com/136326424 Building Elasticsearch: From Idea to {code} to Adoption] The back side of a napkin, a pen, and a few beverages are often the ingredients that yield good ideas. Elasticsearch had a different origin. It started with a need for a simple search box for a collection of recipes. '''Shay Banon''', creator of Elasticsearch and CTO at Elastic, shares the history behind pushing the code for his first open source project that led to the creation of Elasticsearch and it�s rapid adoption by users worldwide. -- ''RISE | August 2015'' == Troubleshooting ==
Make sure that you use the official packages from Elasticsearch, and NOT the Ubuntu packages. See below for the installation guide. Note that I had to actually un-comment and specify the bind.host as 0.0.0.0 on an older setup (Version: 1.7.3, Build: NA/NA, JVM: 1.8.0_171 on Ubuntu 16.04). Plus, make sure that your firewall is allowing the ports 9200-9400. You can run the startup shell script directly to see what's wrong if there's no log output (and read the source for options): <code>/usr/share/elasticsearch/bin/elasticsearch</code>
For version 1.7 on Ubuntu 16.04, although the system uses SystemD, there is still a SysV init script that controls elasticsearch. I think this means that you can't get the logging info into the journalctl system... See /etc/init.d/elasticsearch According to the [https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html install guide], you should be able to edit the elasticsearch.service file, and take out the --quiet option to make it log to the journal. When that is enabled, you can do <code>journalctl --unit elasticsearch</code> to quickly see the info being logged.
== Production Configuration ==
ElasticSearch looks for a configuration file to include, and uses a search path for that include. You can specify it on the command-line; through an environment variable; or just make sure that your file is found in the search path. (My default was found at /usr/share/elasticsearch/bin/elasticsearch.in.sh)
<source lang="bash">
== Elasticsearch for MediaWiki ==
To improve the out-of-the-box search experience with MediaWiki, you should install the [[mw:Extension:CirrusSearch]]. CirrusSearch is just a connector to the Elasticsearch engine. Thus, to use CirrusSearch, first install the [[Elasticsearch]] system (you can use <code>yum</code> or <code>apt</code> repositories for that).
This system has three components: Elastica, CirrusSearch, and Elasticsearch.
; Elastica : Elastica is a MediaWiki extension that provides the library to interface with Elasticsearch. It wraps the [https://github.com/ruflin/Elastica Elastica] library. It has no configuration.
; CirrusSearch : CirrusSearch is a MediaWiki extension that provides search support backed by Elasticsearch.
; Elasticsearch : is a Java application, so you need [[Java]] installed as well. As all these pieces continue to be developed and released, you must be sure to take heed of the requirements for matching the right versions together to compose your full setup.
;Elastica :Elastica is a MediaWiki extension that provides the library to interface with Elasticsearch. It wraps the [https://github.com/ruflin/Elastica Elastica] library. It has no configuration.;CirrusSearch :CirrusSearch is a MediaWiki extension that provides search support backed by Elasticsearch.;Elasticsearch :is a Java application, so you need [[Java]] installed as well. As all these pieces continue to be developed and released, you must be sure to take heed of the requirements for matching the right versions together to compose your full setup. == Elasticsearch for QualityBox ==
<source lang="haproxy">
</source>
== Where is my Elasticsearch? ==
Maybe you installed elasticsearch, but have no idea where it resides on your system. Try this:
<source lang="bash">
The configuration for Elasticsearch is normally held in two files: <code>/etc/elasticsearch/elasticsearch.yml</code> and <code>/etc/elasticsearch/logging.yml</code>
== Starting / Stopping ==
Elasticsearch is (usually) run as a service, so you can start and stop it the way you would depending on whether you run SysV init or SystemD
== Upgrading ==
Old versions of Meza run the legacy REL1_27 release of MediaWiki, while the "beta" Meza runs REL1_28. Our goal should be to run "stable" REL1_29 asap.
{| class="wikitable"
|+ Version Dependencies
|-
! MediaWiki !! ElasticSearch !! Elastica !! CirrusSearch !! Cluster Restart? !! Reindex?
|-
| REL1_27 || 1.x || REL1_27 || REL1_27 || n/a || n/a
|-
| REL1_28 || 2.x || REL1_28 || REL1_28 || restart || yes <ref>For more information about upgrading from 1.x to 2.4, see [https://www.elastic.co/guide/en/elasticsearch/reference/2.4/setup-upgrade.html Upgrading Elasticsearch] in the Elasticsearch 2.4 Reference.</ref>
|-
| REL1_29 || 5.3+ .x or 5.4.x|| REL1_29 || REL1_29 || restart || yes <ref>For more information about upgrading from 2.4 to 5.6, see [https://www.elastic.co/guide/en/elasticsearch/reference/5.6/setup-upgrade.html Upgrading Elasticsearch] in the Elasticsearch 5.6 Reference.</ref>
|-
| REL1_30 || 65.3.x or 5.4.x || REL1_30 || REL1_30 || no <ref>Elasticsearch 6.x support rolling upgrades from Elasticsearch 5.6 Upgrading from earlier versions requires a full cluster restart. See https://www.elastic.co/guide/en/elasticsearch/reference/6.0/restart-upgrade.html</ref> || Depends <ref>Elasticsearch can read indices created in the '''previous major version'''. Older indices must be reindexed or deleted. Elasticsearch will fail to start if incompatible indices are present.</ref>|-|REL 1_31 and 1_32 |''5.5.x or 5.6.x''|||||-|REL 1_33 and !_34 and 1_35|6.5.x (6.5.4 rec)||||
|}
With version 6.0 of ElasticSearch already released, we should immediately upgrade MediaWiki to REL1_29 which is compatible with ElasticSearch 6.x. In the table above es6.x is listed as compatible with mwREL1_30, but in reality we can use es6.x starting in mwREL1_29.
Elastic Co. provides an [https://github.com/elastic/ansible-elasticsearch/tree/master ansible role to manage your installation] (including a [https://github.com/elastic/ansible-elasticsearch/tree/2.x 2.x branch] for older setups). Their [https://www.elastic.co/guide/en/elasticsearch/reference/6.0/setup-upgrade.html guide to upgrading] covers the nitty gritty.
== Reindexing ==
The most basic form of the reindex API just copies documents from one index into another. You might [https://www.elastic.co/guide/en/elasticsearch/reference/6.0/docs-reindex.html reindex] to change the name of a field. Usually though, you are reindexing because you are forced to during a major version upgrade.
== Monitoring ==
With the upgrade to Elasticsearch 5.x and 6.x, plugins are deprecated. It's suggested to use Kibana as a monitoring and management interface to Elasticsearch.
<img src="http://meta.qualitybox.us:20000/api/v1/badge.svg?chart=elasticsearch_local.cluster_health_status&alarm=elasticsearch_last_collected&refresh=auto" />
</html>
* Monitoring the Elastic Stack https://www.elastic.co/guide/en/elastic-stack-overview/6.4/xpack-monitoring.html* Monitoring Settings https://www.elastic.co/guide/en/elasticsearch/reference/6.4/monitoring-settings.html* X-Pack monitoring https://www.elastic.co/guide/en/kibana/current/xpack-monitoring.html* Configuring Monitoring in Kibana https://www.elastic.co/guide/en/kibana/6.4/monitoring-xpack-kibana.html* Monitoring with [https://github.com/lmenezes/cerebro Cerebro]* You can still use [https://mobz.github.io/elasticsearch-head/ elasticsearch-head] if you use an SSH reverse tunnel to access the remote server.
== Installation ==
Here's a quick example of how we got all the parts installed on an [[Ubuntu]] server.
<source lang="bash">
</source>
== Resources == * See [[mw:Help:CirrusSearch]] for help on how to best use the search functionality (including regex searches).* https://phabricator.wikimedia.org/diffusion/ECIR/browse/master/CirrusSearch.php* https://phabricator.wikimedia.org/diffusion/ECIR/browse/master/README* https://wikitech.wikimedia.org/wiki/Search
== Problems ==
We recently ran a 'rebuild-all' script to update Elasticsearch indexes
<pre>
===SOLVED===
You can delete the unwanted index like this with [[curl]]:
<source lang="bash">
curl -XDELETE "http://localhost:9200/wiki_cod_content"
</source>
