Per #31717 this commit changes the defaults to the following:
Batch size of 5120 ops.
Maximum of 12 concurrent read requests.
Maximum of 9 concurrent write requests.
This is not necessarily our final values but it's good to have these as defaults for the purposes of initial testing.
* Change the `TransportPauseFollowAction` to extend from `TransportMasterNodeAction`
instead of `HandledAction`, this removes a sync cluster state api call.
* Introduced `ResponseHandler` that removes duplicated code in `TransportPauseFollowAction` and
`TransportResumeFollowAction`.
* Changed `PauseFollowAction.Request` to not use `readFrom()`.
Both testFollowIndexAndCloseNode and testFailOverOnFollower failed
because they responded to the FollowTask a TransportService closed
exception which is currently considered as a fatal error. This behavior
is not desirable since a closing node can throw that exception, and we
should retry in that case.
This change adds TransportService closed error to the list of retryable
errors.
Closes#34694
As part of this change the leader index name and leader cluster name are
stored in the CCR metadata in the follow index. The resume follow api
will read that when a resume follow request is executed.
Since #34412 and #34474, a follower must have soft-deletes enabled
to work correctly. This change requires soft-deletes on the follower.
Relates #34412
Relates #34474
* Changed the resource id of auto follow patterns to be a user defined name
instead of being the leader cluster alias name.
* Fail when an unfollowed leader index matches with two or more auto follow patterns.
We should be consistent here. We were already using the casing "Ccr" and
this is the preferred casing for Java class names. This commit adjusts
the names of some classes that were using the casing "CCR" to be "Ccr".
In some of our X-Pack REST tests we have to wait for pending tasks to
complete. We are now needing this functionality in ESRestTestCase for
the docs tests where we run against X-Pack features. This commit moves
the helper method that we have in X-Pack to ESRestTestCase, and removes
duplicate logic from waiting for rollup tasks to complete.
Since #34288, we might hit deadlock if the FollowTask has more fetchers
than writers. This can happen in the following scenario:
Suppose the leader has two operations [seq#0, seq#1]; the FollowTask has
two fetchers and one writer.
1. The FollowTask issues two concurrent fetch requests: {from_seq_no: 0,
num_ops:1} and {from_seq_no: 1, num_ops:1} to read seq#0 and seq#1
respectively.
2. The second request which fetches seq#1 completes before, and then it
triggers a write request containing only seq#1.
3. The primary of a follower fails after it has replicated seq#1 to
replicas.
4. Since the old primary did not respond, the FollowTask issues another
write request containing seq#1 (resend the previous write request).
5. The new primary has seq#1 already; thus it won't replicate seq#1 to
replicas but will wait for the global checkpoint to advance at least
seq#1.
The problem is that the FollowTask has only one writer and that writer
is waiting for seq#0 which won't be delivered until the writer completed.
This PR proposes to replicate existing operations with the old primary
term (instead of the current term) on the follower. In particular, when
the following primary detects that it has processed an process already,
it will look up the term of an existing operation with the same seq_no
in the Lucene index, then rewrite that operation with the old term
before replicating it to the following replicas. This approach is
wait-free but requires soft-deletes on the follower.
Relates #34288
Today we rely on the LocalCheckpointTracker to ensure no duplicate when
enabling optimization using max_seq_no_of_updates. The problem is that
the LocalCheckpointTracker is not fully reloaded when opening an engine
with an out-of-order index commit. Suppose the starting commit has seq#0
and seq#2, then the current LocalCheckpointTracker would return "false"
when asking if seq#2 was processed before although seq#2 in the commit.
This change scans the existing sequence numbers in the starting commit,
then marks these as completed in the LocalCheckpointTracker to ensure
the consistent state between LocalCheckpointTracker and Lucene commit.
This change makes it no longer possible to follow / auto follow without
specifying a leader cluster. If a local index needs to be followed
then `cluster.remote.*.seeds` should point to nodes in the local cluster.
Closes#34258
The `AutoFollowTests` needs to restart the clusters between each tests, because
it is using auto follow stats in assertions. Auto follow stats are only reset
by stopping the elected master node.
Extracted the `testGetOperationsBasedOnGlobalSequenceId()` test to its own test, because it just tests the shard changes api.
* Renamed AutoFollowTests to AutoFollowIT, because it is an integration test.
Renamed ShardChangesIT to IndexFollowingIT, because shard changes it the name
of an internal api and isn't a good name for an integration test.
* move creation of NodeConfigurationSource to a seperate method
* Fixes issues after merge, moved assertSeqNos() and assertSameDocIdsOnShards() methods from ESIntegTestCase to InternalTestCluster, so that ccr tests can use these methods too.
Today we rewrite the operations from the leader with the term of the
following primary because the follower should own its history. The
problem is that a newly promoted primary may re-assign its term to
operations which were replicated to replicas before by the previous
primary. If this happens, some operations with the same seq_no may be
assigned different terms. This is not good for the future optimistic
locking using a combination of seqno and term.
This change ensures that the primary of a follower only processes an
operation if that operation was not processed before. The skipped
operations are guaranteed to be delivered to replicas via either
primary-replica resync or peer-recovery. However, the primary must not
acknowledge until the global checkpoint is at least the highest seqno of
all skipped ops (i.e., they all have been processed on every replica).
Relates #31751
Relates #31113
Also fixed ShardFollowNodeTaskTests to not return ops when responseSize
is empty. Otherwise ops are returned when no ops are expected to be returned.
Co-authored-by: Jason Tedor <jason@tedor.me>
Unfollow should be allowed / disallowed on a per index level instead of
cluster level.
Also renamed `create_follow_index` index privilege to
`manage_follow_index` privilege and include unfollow and close APIs.
This commit modifies the follow stats API response structure to more
clearly highlight meaning of the higher level fields. In particular,
previously the response had a top-level key for each index. Instead, we
nest the indices under an "indices" field which is now an array. The
values in this array are objects containing two fields: "index" which is
the name of the follower index, and "shards" which is an array where
each value in the array is the follower stats for that shard. That is,
we have gone from:
{
"bar": [
{
"shard_id": 0...
}...
]...
}
to
{
"indices": [
{
"index": "bar",
"shards": [
{
"shard_id": 0...
}...
]
}...
}
In the CCR docs we want to refer to the endpoint that returns following
stats as the follow stats API. This commit renames the internal
implementation of this endpoint to reflect this usage.
The follower index shard history UUID will be fetched from the indices stats api when the shard follow task starts and will be provided with the bulk shard operation requests. The bulk shard operations api will fail if the provided history uuid is unequal to the actual history uuid.
No longer record the leader history uuid in shard follow task params, but rather use the leader history UUIDs directly from follower index's custom metadata. The resume follow api will remain to fail if leader index shard history UUIDs are missing.
Closes#33956
Since #34099, the FollowingEngine will skip an operation which was
already processed before. With that change, it should be okay to unmute
testFollowIndexAndCloseNode.
This arose when two commits were pushed at roughly the same time, both
of which compiled successfully against master, but not when taken
together. This commit fixes a reference in one of the commits that was
changed in the other commit.
This commit modifies the CCR stats endpoint for indices to be
/{index}/_ccr/stats. This makes this endpoint consistent with other
index-centric endpoints like indices stats.
The unfollow API changes a follower index into a regular index, so that it will accept write requests from clients.
For the unfollow api to work the index follow needs to be stopped and the index needs to be closed.
Closes#33931
This change introduces the indexing optimization using sequence numbers
in the FollowingEngine. This optimization uses the max_seq_no_updates
which is tracked on the primary of the leader and replicated to replicas
and followers.
Relates #33656
Prior to following an index in the follow API, check whether current
user has sufficient privileges in the leader cluster to read and
monitor the leader index.
Also check this in the create and follow API prior to creating the
follow index.
Also introduced READ_CCR cluster privilege that include the minimal
cluster level actions that are required for ccr in the leader cluster.
So a user can follow indices in a cluster, but not use the ccr admin APIs.
Closes#33553
Co-authored-by: Jason Tedor <jason@tedor.me>
The following changes were made:
* Added ElasticsearchSecurityException. For in the case the current user has insufficient privileges while an index is being followed. Prior to following ccr checks whether the current user has sufficient privileges and if not the follow api fails with an error.
* Added Index block exception. If the leader index gets closed, this exception is returned.
* Added ClusterBlockException service unavailable. In case for example the leader cluster is without elected master.
* Removed IndexNotFoundException. If the leader / follower index has been deleted, ccr will need to stop the shard follow tasks with an error.
Closes#33954
