Graceful shutdown
You can configure the graceful shutdown as described in Graceful shutdown.
Nodes
As a default, OpenSearch nodes have 2 minutes to shut down gracefully.
The OpenSearch node process will receive a SIGTERM signal when Kubernetes wants to terminate the Pod.
It will log the received signal as shown in the log below and initiate a graceful shutdown.
After the graceful shutdown timeout runs out, and the process still did not exit, Kubernetes will issue a SIGKILL signal.
[o.o.s.a.r.AuditMessageRouter] Closing AuditMessageRouter
[o.o.n.Node ] stopping ...
[o.o.s.a.s.SinkProvider ] Closing DebugSink
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-3}{jcXCasAwSf6wTxND431bnw}{KFX1ua4GQpOZc1wdfY5RdA}{10.244.0.22}{10.244.0.22:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} disconnected
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-0}{_HWwfRHWSk-0l2FIYWZerw}{voEOdPrxRsifVO0fema60Q}{10.244.0.26}{10.244.0.26:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} disconnected
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-3}{jcXCasAwSf6wTxND431bnw}{KFX1ua4GQpOZc1wdfY5RdA}{10.244.0.22}{10.244.0.22:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} marking
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-2}{NudYVGdNSbClz-e09TVElg}{MmWiswEsQo6MpuDG47a6Ag}{10.244.0.24}{10.244.0.24:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} disconnected
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-1}{NSxqrrevSIOtCIWz9Hd9vw}{qHNTBP4NTqe09_-9ZqnUJQ}{10.244.0.25}{10.244.0.25:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} disconnected
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-0}{_HWwfRHWSk-0l2FIYWZerw}{voEOdPrxRsifVO0fema60Q}{10.244.0.26}{10.244.0.26:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} marking
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-1}{NSxqrrevSIOtCIWz9Hd9vw}{qHNTBP4NTqe09_-9ZqnUJQ}{10.244.0.25}{10.244.0.25:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} marking
[o.o.c.c.FollowersChecker ] FollowerChecker{discoveryNode={simple-opensearch-nodes-default-2}{NudYVGdNSbClz-e09TVElg}{MmWiswEsQo6MpuDG47a6Ag}{10.244.0.24}{10.244.0.24:9300}{dimr}{shard_indexing_pressure_enabled=true}, failureCountSinceLastSuccess=0, [cluster.fault_detection.follower_check.retry_count]=3} marking
[o.o.n.Node ] stopped
[o.o.n.Node ] closing ...
[o.o.s.a.i.AuditLogImpl ] Closing AuditLogImpl
[o.o.n.Node ] closed