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https://issues.apache.org/jira/browse/PHOENIX-6273?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17269697#comment-17269697
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ASF GitHub Bot commented on PHOENIX-6273:
-----------------------------------------
sakshamgangwar commented on a change in pull request #1079:
URL: https://github.com/apache/phoenix/pull/1079#discussion_r562264530
##########
File path:
phoenix-core/src/main/java/org/apache/phoenix/iterate/TableSnapshotResultIterator.java
##########
@@ -80,7 +81,12 @@ public TableSnapshotResultIterator(Configuration
configuration, Scan scan, ScanM
this.scan = scan;
this.scanMetricsHolder = scanMetricsHolder;
this.scanIterator = UNINITIALIZED_SCANNER;
- this.restoreDir = new
Path(configuration.get(PhoenixConfigurationUtil.RESTORE_DIR_KEY));
+ if (PhoenixConfigurationUtil.isMRSnapshotManagedExternally(configuration))
{
+ this.restoreDir = new
Path(configuration.get(PhoenixConfigurationUtil.RESTORE_DIR_KEY));
+ } else {
+ this.restoreDir = new
Path(configuration.get(PhoenixConfigurationUtil.RESTORE_DIR_KEY),
Review comment:
@gjacoby126 that existed before this change as well, this is not a
necessary code, I believe at job level in PhoenixMapReduceUtil we update the
configuration restoreDir to a new path so as to make sure that even if
restoreDir configuration sent from the caller is same for multiple jobs, it
should be able to handle it internally by adding a new sub-directory (which we
are also doing at scan level too :) ). Whereas in externally managed now we
take full responsibility for the restoreDir creation/usage/deletion.
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> Add support to handle MR Snapshot restore externally
> ----------------------------------------------------
>
> Key: PHOENIX-6273
> URL: https://issues.apache.org/jira/browse/PHOENIX-6273
> Project: Phoenix
> Issue Type: Bug
> Components: core
> Affects Versions: 5.0.0, 4.14.3
> Reporter: Saksham Gangwar
> Assignee: Saksham Gangwar
> Priority: Major
> Fix For: 5.1.0, 4.16.0
>
>
> Recently we switched an MR application from scanning live tables to scanning
> snapshots (PHOENIX-3744). We ran into a severe performance issue, which
> turned out to a correctness issue due to over-lapping scan splits generation.
> After some debugging we figured that it has been fixed via PHOENIX-4997.
> We also *need not restore the snapshot per map task*. Currently, we restore
> the snapshot once per map task into a temp directory. For large tables on big
> clusters, this creates a storm of NN RPCs. We can do this once per job and
> let all the map tasks operate on the same restored snapshot. HBase already
> did this via HBASE-18806, we can do something similar. Jira to correct this
> behavior: https://issues.apache.org/jira/browse/PHOENIX-6334
> *The purpose of this Jira* is to resolve this issue immediately by providing
> the ability to the caller to decide whether or not snapshot restore needs to
> be handled externally or internally on the Phoenix side (the buggy approach).
> All other performance suggestions here:
> https://issues.apache.org/jira/browse/PHOENIX-6081
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