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https://issues.apache.org/jira/browse/IGNITE-17738?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Anton Vinogradov updated IGNITE-17738:
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Description:
On cluster restart (because of power-off, OOM or some other problem) it's
possible to have PDS inconsistent (primary partitions may contain operations
missed on backups as well as counters may contain gaps even on primary).
1) Currently, "historical rebalance" is able to sync the data to the highest
LWM for every partition.
Most likely, a primary will be chosen as a rebalance source, but the data after
the LWM will not be rebalanced. So, all updates between LWM and HWM will not be
synchronized.
Such partition may be rebalanced correctly "later" in case of full rebalance
will be triggered sometime.
2) In case LWM is the same on primary and backup, rebalance will never happen
for such partition.
A possible solution for the case when the cluster failed and restarted (same
baseline) is to fix the counters automatically (when cluster composition is
equal to the baseline specified before the crash).
Counters should be set as
- HWM at primary and as LWM at backups for caches with 2+ backups,
- LWM at primary and as HWM at backups for caches with a single backup.
was:
On cluster restart (because of power-off, OOM or some other problem) it's
possible to have PDS inconsistent (primary partitions may contain operations
missed on backups as well as counters may contain gaps even on primary).
1) Currently, "historical rebalance" is able to sync the data to the highest
LWM for every partition.
Most likely, a primary will be chosen as a rebalance source, but the data after
the LWM will not be rebalanced. So, all updates between LWM and HWM will not be
synchronized.
Such partition may be rebalanced correctly "later" in case full rebalance will
be triggered sometime.
2) In case LWM is the same on primary and backup, rebalance will never happen
for such partition.
A possible solution for the case when the cluster failed and restarted (same
baseline) is to fix the counters automatically (when cluster composition is
equal to the baseline specified before the crash).
Counters should be set as
- HWM at primary and as LWM at backups for caches with 2+ backups,
- LWM at primary and as HWM at backups for caches with a single backup.
> Cluster must be able to fix the inconsistency on restart by itself
> ------------------------------------------------------------------
>
> Key: IGNITE-17738
> URL: https://issues.apache.org/jira/browse/IGNITE-17738
> Project: Ignite
> Issue Type: Sub-task
> Reporter: Anton Vinogradov
> Priority: Major
> Labels: iep-31, ise
>
> On cluster restart (because of power-off, OOM or some other problem) it's
> possible to have PDS inconsistent (primary partitions may contain operations
> missed on backups as well as counters may contain gaps even on primary).
> 1) Currently, "historical rebalance" is able to sync the data to the highest
> LWM for every partition.
> Most likely, a primary will be chosen as a rebalance source, but the data
> after the LWM will not be rebalanced. So, all updates between LWM and HWM
> will not be synchronized.
> Such partition may be rebalanced correctly "later" in case of full rebalance
> will be triggered sometime.
> 2) In case LWM is the same on primary and backup, rebalance will never happen
> for such partition.
> A possible solution for the case when the cluster failed and restarted (same
> baseline) is to fix the counters automatically (when cluster composition is
> equal to the baseline specified before the crash).
> Counters should be set as
> - HWM at primary and as LWM at backups for caches with 2+ backups,
> - LWM at primary and as HWM at backups for caches with a single backup.
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