…xisting indices (#38177)

When restoring shards of existing indices, the RestoreService also 
restores the values of primary terms stored in the snapshot index 
metadata. The primary terms are not updated and could potentially 
conflict with current index primary terms if the restored primary terms 
are lower than the existing ones.

This situation is likely to happen with replicated closed indices 
(because primary terms are increased when the index is transitioning 
from open to closed state, and the snapshotted primary terms are the
 one at the time the index was opened) (see #38024) and maybe also 
with CCR.

This commit changes the RestoreService so that it updates the primary 
terms using the maximum value between the snapshotted values and 
the existing values.

Related to #33888

…xisting indices (elastic#38177)

When restoring shards of existing indices, the RestoreService also
restores the values of primary terms stored in the snapshot index
metadata. The primary terms are not updated and could potentially
conflict with current index primary terms if the restored primary terms
are lower than the existing ones.

This situation is likely to happen with replicated closed indices
(because primary terms are increased when the index is transitioning
from open to closed state, and the snapshotted primary terms are the
one at the time the index was opened) (see elastic#38024) and maybe also
with CCR.

This commit changes the RestoreService so that it updates the primary
terms using the maximum value between the snapshotted values and
the existing values.

Backport elastic/elasticsearch@da6269b

Related to elastic#33888

…xisting indices (#38177)

When restoring shards of existing indices, the RestoreService also
restores the values of primary terms stored in the snapshot index
metadata. The primary terms are not updated and could potentially
conflict with current index primary terms if the restored primary terms
are lower than the existing ones.

This situation is likely to happen with replicated closed indices
(because primary terms are increased when the index is transitioning
from open to closed state, and the snapshotted primary terms are the
one at the time the index was opened) (see #38024) and maybe also
with CCR.

This commit changes the RestoreService so that it updates the primary
terms using the maximum value between the snapshotted values and
the existing values.

Backport da6269b

Related to #33888

…38327)

Relates to #33888 and  #38024

Before this change, closed indexes were simply not replicated. It was therefore 
possible to close an index and then decommission a data node without knowing 
that this data node contained shards of the closed index, potentially leading to 
data loss. Shards of closed indices were not completely taken into account when 
balancing the shards within the cluster, or automatically replicated through shard 
copies, and they were not easily movable from node A to node B using APIs like 
Cluster Reroute without being fully reopened and closed again.

This commit changes the logic executed when closing an index, so that its shards 
are not just removed and forgotten but are instead reinitialized and reallocated on 
data nodes using an engine implementation which does not allow searching or
 indexing, which has a low memory overhead (compared with searchable/indexable 
opened shards) and which allows shards to be recovered from peer or promoted 
as primaries when needed.

This new closing logic is built on top of the new Close Index API introduced in 
6.7.0 (#37359). Some pre-closing sanity checks are executed on the shards before 
closing them, and closing an index on a 8.0 cluster will reinitialize the index shards 
and therefore impact the cluster health.

Some APIs have been adapted to make them work with closed indices:
- Cluster Health API
- Cluster Reroute API
- Cluster Allocation Explain API
- Recovery API
- Cat Indices
- Cat Shards
- Cat Health
- Cat Recovery

This commit contains all the following changes (most recent first):
* c6c42a1 Adapt NoOpEngineTests after #39006
* 3f9993d Wait for shards to be active after closing indices (#38854)
* 5e7a428 Adapt the Cluster Health API to closed indices (#39364)
* 3e61939 Adapt CloseFollowerIndexIT for replicated closed indices (#38767)
* 71f5c34 Recover closed indices after a full cluster restart (#39249)
* 4db7fd9 Adapt the Recovery API for closed indices (#38421)
* 4fd1bb2 Adapt more tests suites to closed indices (#39186)
* 0519016 Add replica to primary promotion test for closed indices (#39110)
* b756f6c Test the Cluster Shard Allocation Explain API with closed indices (#38631)
* c484c66 Remove index routing table of closed indices in mixed versions clusters (#38955)
* 00f1828 Mute CloseFollowerIndexIT.testCloseAndReopenFollowerIndex()
* e845b0a Do not schedule Refresh/Translog/GlobalCheckpoint tasks for closed indices (#38329)
* cf9a015 Adapt testIndexCanChangeCustomDataPath for replicated closed indices (#38327)
* b9becdd Adapt testPendingTasks() for replicated closed indices (#38326)
* 02cc730 Allow shards of closed indices to be replicated as regular shards (#38024)
* e53a9be Fix compilation error in IndexShardIT after merge with master
* cae4155 Relax NoOpEngine constraints (#37413)
* 54d110b [RCI] Adapt NoOpEngine to latest FrozenEngine changes
* c63fd69 [RCI] Add NoOpEngine for closed indices (#33903)

Relates to #33888

…astic#38024)

This commit allows shards of indices in CLOSE state to be replicated as normal shards. 
It changes the MetaDataIndexStateService so that index routing tables of closed indices 
are kept in cluster state when the index is closed. Index routing tables are modified so 
that shard routings are reinitialized with the INDEX_CLOSED unassigned information. 
The IndicesClusterStateService is modified to remove IndexService instances of closed 
or reopened indices. In combination with the ShardRouting being in INITIALIZING state 
the shards are recreated on the data nodes to reflect the new state. If the index state is 
closed, the IndexShard instances will be created using the NoOpEngine as the engine
implementation.

This commit also mutes two tests that rely on the fact that shard locks are released when 
an index is closed, which is not the case anymore with replicated closed indices (actually 
the locks are released but reacquired once the shard is reinitialized after being closed). 
These tests will be adapted in follow up PRs.

Finally, many things will require to be adapted or improved in follow up PRs (see elastic#33888)
 but this is the first big step towards replicated closed indices.

Relates to elastic#33888

…lastic#38327)

Relates to elastic#33888 and  elastic#38024

Backport support for replicating closed indices (#39499)
    
    Before this change, closed indexes were simply not replicated. It was therefore
    possible to close an index and then decommission a data node without knowing
    that this data node contained shards of the closed index, potentially leading to
    data loss. Shards of closed indices were not completely taken into account when
    balancing the shards within the cluster, or automatically replicated through shard
    copies, and they were not easily movable from node A to node B using APIs like
    Cluster Reroute without being fully reopened and closed again.
    
    This commit changes the logic executed when closing an index, so that its shards
    are not just removed and forgotten but are instead reinitialized and reallocated on
    data nodes using an engine implementation which does not allow searching or
     indexing, which has a low memory overhead (compared with searchable/indexable
    opened shards) and which allows shards to be recovered from peer or promoted
    as primaries when needed.
    
    This new closing logic is built on top of the new Close Index API introduced in
    6.7.0 (#37359). Some pre-closing sanity checks are executed on the shards before
    closing them, and closing an index on a 8.0 cluster will reinitialize the index shards
    and therefore impact the cluster health.
    
    Some APIs have been adapted to make them work with closed indices:
    - Cluster Health API
    - Cluster Reroute API
    - Cluster Allocation Explain API
    - Recovery API
    - Cat Indices
    - Cat Shards
    - Cat Health
    - Cat Recovery
    
    This commit contains all the following changes (most recent first):
    * c6c42a1 Adapt NoOpEngineTests after #39006
    * 3f9993d Wait for shards to be active after closing indices (#38854)
    * 5e7a428 Adapt the Cluster Health API to closed indices (#39364)
    * 3e61939 Adapt CloseFollowerIndexIT for replicated closed indices (#38767)
    * 71f5c34 Recover closed indices after a full cluster restart (#39249)
    * 4db7fd9 Adapt the Recovery API for closed indices (#38421)
    * 4fd1bb2 Adapt more tests suites to closed indices (#39186)
    * 0519016 Add replica to primary promotion test for closed indices (#39110)
    * b756f6c Test the Cluster Shard Allocation Explain API with closed indices (#38631)
    * c484c66 Remove index routing table of closed indices in mixed versions clusters (#38955)
    * 00f1828 Mute CloseFollowerIndexIT.testCloseAndReopenFollowerIndex()
    * e845b0a Do not schedule Refresh/Translog/GlobalCheckpoint tasks for closed indices (#38329)
    * cf9a015 Adapt testIndexCanChangeCustomDataPath for replicated closed indices (#38327)
    * b9becdd Adapt testPendingTasks() for replicated closed indices (#38326)
    * 02cc730 Allow shards of closed indices to be replicated as regular shards (#38024)
    * e53a9be Fix compilation error in IndexShardIT after merge with master
    * cae4155 Relax NoOpEngine constraints (#37413)
    * 54d110b [RCI] Adapt NoOpEngine to latest FrozenEngine changes
    * c63fd69 [RCI] Add NoOpEngine for closed indices (#33903)
    
    Relates to #33888