[
https://issues.apache.org/jira/browse/HBASE-26811?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
chenglei updated HBASE-26811:
-----------------------------
Description:
For read replica, when I set {{hbase.region.replica.wait.for.primary.flush}} to
false, and set {{TableDescriptorBuilder.setRegionMemStoreReplication}} to true
explicitly at table level, the secondary replica would be disabled for read
forever, reading on this replica region would always throw :
{code:java}
java.io.IOException: The region's reads are disabled. Cannot serve the request
at
org.apache.hadoop.hbase.regionserver.HRegion.checkReadsEnabled(HRegion.java:5187)
at
org.apache.hadoop.hbase.regionserver.HRegion.startRegionOperation(HRegion.java:8279)
{code}
Very strange, if I don't
{{TableDescriptorBuilder.setRegionMemStoreReplication}} to true explicitly
(which default value is true), the secondary replica is normal.
This problem is because when set
{{hbase.region.replica.wait.for.primary.flush}} to false, the
{{HRegionServer.startServices}} would not create the
{{ExecutorType.RS_REGION_REPLICA_FLUSH_OPS}} for {{RegionReplicaFlushHandler}}
at global level:
{code:java}
if
(ServerRegionReplicaUtil.isRegionReplicaWaitForPrimaryFlushEnabled(conf)) {
final int regionReplicaFlushThreads = conf.getInt(
"hbase.regionserver.region.replica.flusher.threads", conf.getInt(
"hbase.regionserver.executor.openregion.threads", 3));
executorService.startExecutorService(executorService.new
ExecutorConfig().setExecutorType(
ExecutorType.RS_REGION_REPLICA_FLUSH_OPS).setCorePoolSize(regionReplicaFlushThreads));
}
{code:java}
but when I set {{TableDescriptorBuilder.setRegionMemStoreReplication}} to true
explicitly, it also set {{hbase.region.replica.wait.for.primary.flush}} to true
at table-level(there is no public
{{hbase.region.replica.wait.for.primary.flush} config for hbase user at
table-level):
{code:java}
public ModifyableTableDescriptor setRegionMemStoreReplication(boolean
memstoreReplication) {
setValue(REGION_MEMSTORE_REPLICATION_KEY,
Boolean.toString(memstoreReplication));
// If the memstore replication is setup, we do not have to wait for
observing a flush event
// from primary before starting to serve reads, because gaps from
replication is not applicable
return setValue(REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY,
Boolean.toString(memstoreReplication));
}
{code}
So when the secondary replica region is
open,{{HRegionServer.triggerFlushInPrimaryRegion}} is invoked for this region,
because {{hbase.region.replica.wait.for.primary.flush}} to true at table-level,
the line 2234 is skipped, secondary replica is disabled for read at line 2238,
but there is no {{ExecutorType.RS_REGION_REPLICA_FLUSH_OPS}} for
{{RegionReplicaFlushHandler}} at HRegionServer-level, so line 2243 would not
schedule {{RegionReplicaFlushHandler}}, the secondary replica would be disabled
for read forever.
{code:java}
2227 private void triggerFlushInPrimaryRegion(final HRegion region) {
...
2232 if
(!ServerRegionReplicaUtil.isRegionReplicaReplicationEnabled(region.conf, tn) ||
2233
!ServerRegionReplicaUtil.isRegionReplicaWaitForPrimaryFlushEnabled(region.conf))
{
2234 region.setReadsEnabled(true);
2235 return;
2236 }
2237
2238 region.setReadsEnabled(false); // disable reads before marking the
region as opened.
2239 // RegionReplicaFlushHandler might reset this.
2240
2241 // Submit it to be handled by one of the handlers so that we do not
block OpenRegionHandler
2242 if (this.executorService != null) {
2243 this.executorService.submit(new RegionReplicaFlushHandler(this,
region));
2244 } else {
...
}
}
{{code}}
> Secondary replica may be disabled for read forever
> --------------------------------------------------
>
> Key: HBASE-26811
> URL: https://issues.apache.org/jira/browse/HBASE-26811
> Project: HBase
> Issue Type: Bug
> Components: read replicas
> Affects Versions: 3.0.0-alpha-2, 2.4.10
> Reporter: chenglei
> Priority: Major
>
> For read replica, when I set {{hbase.region.replica.wait.for.primary.flush}}
> to false, and set {{TableDescriptorBuilder.setRegionMemStoreReplication}} to
> true explicitly at table level, the secondary replica would be disabled for
> read forever, reading on this replica region would always throw :
> {code:java}
> java.io.IOException: The region's reads are disabled. Cannot serve the
> request
> at
> org.apache.hadoop.hbase.regionserver.HRegion.checkReadsEnabled(HRegion.java:5187)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.startRegionOperation(HRegion.java:8279)
> {code}
> Very strange, if I don't
> {{TableDescriptorBuilder.setRegionMemStoreReplication}} to true explicitly
> (which default value is true), the secondary replica is normal.
> This problem is because when set
> {{hbase.region.replica.wait.for.primary.flush}} to false, the
> {{HRegionServer.startServices}} would not create the
> {{ExecutorType.RS_REGION_REPLICA_FLUSH_OPS}} for
> {{RegionReplicaFlushHandler}} at global level:
> {code:java}
> if
> (ServerRegionReplicaUtil.isRegionReplicaWaitForPrimaryFlushEnabled(conf)) {
> final int regionReplicaFlushThreads = conf.getInt(
> "hbase.regionserver.region.replica.flusher.threads", conf.getInt(
> "hbase.regionserver.executor.openregion.threads", 3));
> executorService.startExecutorService(executorService.new
> ExecutorConfig().setExecutorType(
>
> ExecutorType.RS_REGION_REPLICA_FLUSH_OPS).setCorePoolSize(regionReplicaFlushThreads));
> }
> {code:java}
> but when I set {{TableDescriptorBuilder.setRegionMemStoreReplication}} to
> true explicitly, it also set {{hbase.region.replica.wait.for.primary.flush}}
> to true at table-level(there is no public
> {{hbase.region.replica.wait.for.primary.flush} config for hbase user at
> table-level):
> {code:java}
> public ModifyableTableDescriptor setRegionMemStoreReplication(boolean
> memstoreReplication) {
> setValue(REGION_MEMSTORE_REPLICATION_KEY,
> Boolean.toString(memstoreReplication));
> // If the memstore replication is setup, we do not have to wait for
> observing a flush event
> // from primary before starting to serve reads, because gaps from
> replication is not applicable
> return setValue(REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY,
> Boolean.toString(memstoreReplication));
> }
> {code}
> So when the secondary replica region is
> open,{{HRegionServer.triggerFlushInPrimaryRegion}} is invoked for this
> region, because {{hbase.region.replica.wait.for.primary.flush}} to true at
> table-level, the line 2234 is skipped, secondary replica is disabled for read
> at line 2238, but there is no {{ExecutorType.RS_REGION_REPLICA_FLUSH_OPS}}
> for {{RegionReplicaFlushHandler}} at HRegionServer-level, so line 2243 would
> not schedule {{RegionReplicaFlushHandler}}, the secondary replica would be
> disabled for read forever.
> {code:java}
> 2227 private void triggerFlushInPrimaryRegion(final HRegion region) {
> ...
> 2232 if
> (!ServerRegionReplicaUtil.isRegionReplicaReplicationEnabled(region.conf, tn)
> ||
> 2233
> !ServerRegionReplicaUtil.isRegionReplicaWaitForPrimaryFlushEnabled(region.conf))
> {
> 2234 region.setReadsEnabled(true);
> 2235 return;
> 2236 }
> 2237
> 2238 region.setReadsEnabled(false); // disable reads before marking the
> region as opened.
> 2239 // RegionReplicaFlushHandler might reset this.
> 2240
> 2241 // Submit it to be handled by one of the handlers so that we do not
> block OpenRegionHandler
> 2242 if (this.executorService != null) {
> 2243 this.executorService.submit(new RegionReplicaFlushHandler(this,
> region));
> 2244 } else {
> ...
> }
> }
> {{code}}
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