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This adds a low level primitive operations to shrink an existing index into a new index with a single shard. This primitive expects all shards of the source index to allocated on a single node. Once the target index is initializing on the shrink node it takes a snapshot of the source index shards and copies all files into the target indices data folder. An [optimization](https://issues.apache.org/jira/browse/LUCENE-7300) coming in Lucene 6.1 will also allow for optional constant time copy if hard-links are supported by the filesystem. All mappings are merged into the new indexes metadata once the snapshots have been taken on the merge node. To shrink an existing index all shards must be moved to a single node (one instance of each shard) and the index must be read-only: ```BASH $ curl -XPUT 'http://localhost:9200/logs/_settings' -d '{ "settings" : { "index.routing.allocation.require._name" : "shrink_node_name", "index.blocks.write" : true } } ``` once all shards are started on the shrink node. the new index can be created via: ```BASH $ curl -XPUT 'http://localhost:9200/logs/_shrink/logs_single_shard' -d '{ "settings" : { "index.codec" : "best_compression", "index.number_of_replicas" : 1 } }' ``` This API will perform all needed check before the new index is created and selects the shrink node based on the allocation of the source index. This call returns immediately, to monitor shrink progress the recovery API should be used since all copy operations are reflected in the recovery API with byte copy progress etc. The shrink operation does not modify the source index, if a shrink operation should be canceled or if the shrink failed, the target index can simply be deleted and all resources are released.
The Elasticsearch docs are in AsciiDoc format and can be built using the Elasticsearch documentation build process. See: https://github.com/elastic/docs Snippets marked with `// CONSOLE` are automatically annotated with "VIEW IN SENSE" in the documentation and are automatically tested by the command `gradle :docs:check`. By default `// CONSOLE` snippet runs as its own isolated test. You can manipulate the test execution in the following ways: * `// TEST`: Explicitly marks a snippet as a test. Snippets marked this way are tests even if they don't have `// CONSOLE`. * `// TEST[s/foo/bar/]`: Replace `foo` with `bar` in the test. This should be used sparingly because it makes the test "lie". Sometimes, though, you can use it to make the tests more clear. * `// TEST[catch:foo]`: Used to expect errors in the requests. Replace `foo` with `request` to expect a 400 error, for example. If the snippet contains multiple requests then only the last request will expect the error. * `// TEST[continued]`: Continue the test started in the last snippet. Between tests the nodes are cleaned: indexes are removed, etc. This will prevent that. This is really useful when you have text and snippets that work together to tell the story of some use case because it merges the snippets (and thus the use case) into one big test. * `// TEST[skip:reason]`: Skip this test. Replace `reason` with the actual reason to skip the test. Snippets without `// TEST` or `// CONSOLE` aren't considered tests anyway but this is useful for explicitly documenting the reason why the test shouldn't be run. * `// TEST[setup:name]`: Run some setup code before running the snippet. This is useful for creating and populating indexes used in the snippet. The setup code is defined in `docs/build.gradle`. * `// TESTRESPONSE`: Matches this snippet against the body of the response of the last test. If the response is JSON then order is ignored. With `// TEST[continued]` you can make tests that contain multiple command snippets and multiple response snippets. * `// TESTRESPONSE[s/foo/bar/]`: Substitutions. See `// TEST[s/foo/bar]`. * `// TESTSETUP`: Marks this snippet as the "setup" for all other snippets in this file. This is a somewhat natural way of structuring documentation. You say "this is the data we use to explain this feature" then you add the snippet that you mark `// TESTSETUP` and then every snippet will turn into a test that runs the setup snippet first. See the "painless" docs for a file that puts this to good use. This is fairly similar to `// TEST[setup:name]` but rather than the setup defined in `docs/build.gradle` the setup is defined right in the documentation file. Any place you can use json you can use elements like `$body.path.to.thing` which is replaced on the fly with the contents of the thing at `path.to.thing` in the last response.