Node IDs are currently randomly generated during node startup. That means they change every time the node is restarted. While this doesn't matter for ES proper, it makes it hard for external services to track nodes. Another, more minor, side effect is that indexing the output of, say, the node stats API results in creating new fields due to node ID being used as keys.
The first approach I considered was to use the node's published address as the base for the id. We already [treat nodes with the same address as the same](https://github.com/elastic/elasticsearch/blob/master/core/src/main/java/org/elasticsearch/discovery/zen/NodeJoinController.java#L387) so this is a simple change (see [here](https://github.com/elastic/elasticsearch/compare/master...bleskes:node_persistent_id_based_on_address)). While this is simple and it works for probably most cases, it is not perfect. For example, if after a node restart, the node is not able to bind to the same port (because it's not yet freed by the OS), it will cause the node to still change identity. Also in environments where the host IP can change due to a host restart, identity will not be the same.
Due to those limitation, I opted to go with a different approach where the node id will be persisted in the node's data folder. This has the upside of connecting the id to the nodes data. It also means that the host can be adapted in any way (replace network cards, attach storage to a new VM). I
It does however also have downsides - we now run the risk of two nodes having the same id, if someone copies clones a data folder from one node to another. To mitigate this I changed the semantics of the protection against multiple nodes with the same address to be stricter - it will now reject the incoming join if a node exists with the same id but a different address. Note that if the existing node doesn't respond to pings (i.e., it's not alive) it will be removed and the new node will be accepted when it tries another join.
Last, and most importantly, this change requires that *all* nodes persist data to disk. This is a change from current behavior where only data & master nodes store local files. This is the main reason for marking this PR as breaking.
Other less important notes:
- DummyTransportAddress is removed as we need a unique network address per node. Use `LocalTransportAddress.buildUnique()` instead.
- I renamed `node.add_lid_to_custom_path` to `node.add_lock_id_to_custom_path` to avoid confusion with the node ID which is now part of the `NodeEnvironment` logic.
- I removed the `version` paramater from `MetaDataStateFormat#write` , it wasn't really used and was just in the way :)
- TribeNodes are special in the sense that they do start multiple sub-nodes (previously known as client nodes). Those sub-nodes do not store local files but derive their ID from the parent node id, so they are generated consistently.
Today we allow to shrink to 1 shard but that might not be possible due to
too many document or a single shard doesn't meet the requirements for the index.
The logic can be expanded to N shards if the source index shards is a multiple of N.
This guarantees that there are not hotspots created due to different number of shards
being shrunk into one.
Today we use `index.routing.allocation.include._id` to filter the allocation
for the shrink target index. That has the sideeffect that the user has to
delete that setting / change it once the primary has been recovered (shrink is done)
This PR adds a dedicated filter that can only be set internally that only filters
allocation for unassigned shards.
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.
Adds infrastructure so `gradle :docs:check` will extract tests from
snippets in the documentation and execute the tests. This is included
in `gradle check` so it should happen on CI and during a normal build.
By default each `// AUTOSENSE` snippet creates a unique REST test. These
tests are executed in a random order and the cluster is wiped between
each one. If multiple snippets chain together into a test you can annotate
all snippets after the first with `// TEST[continued]` to have the
generated tests for both snippets joined.
Snippets marked as `// TESTRESPONSE` are checked against the response
of the last action.
See docs/README.asciidoc for lots more.
Closes#12583. That issue is about catching bugs in the docs during build.
This catches *some* bugs in the docs during build which is a good start.
Closes#17513
The current example in the documentation for Index Templates lacks any properties values. This is helpful to many devs that aren't sure how to take a regular Index Mapping and convert it to a template.
Use 'includeSegmentFileSizes' as the flag name to report disk usage.
Added test that verifies reported segment disk usage is growing accordingly after adding a document.
Documentation: Reference the new parameter as part of indices stats.
Warmers are now barely useful and will be removed in 3.0. Note that this only
removes the warmer API and query-based warmers. We still have warmers internally
for eg. global ordinals.
Close#15607
Resolves conflicts between parent routing and alias routing with the following rule:
* The parent routing is ignored if there is an alias routing that matches the request.
Closes#3068
This adds an API for force merging lucene segments. The `/_optimize` API is now
deprecated and replaced by the `/_forcemerge` API, which has all the same flags
and action, just a different name.
Sho Minagawa
Glen Smith
Christoph Wurm
Boaz Leskes
debadair
Areek Zillur
Simon Willnauer
Clinton Gormley
Shane Connelly
Zack Dever
Nik Everett
Josef Salyer
Jun Ohtani
Mahmoud Lababidi
Adrien Grand
Camilo Díaz Repka
Lee Hinman
Dongjoon Hyun
Yannick Welsch
Chris Earle
Jim Ferenczi
Brady Vidovic