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https://issues.apache.org/jira/browse/DRILL-5516?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16014783#comment-16014783
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ASF GitHub Bot commented on DRILL-5516:
---------------------------------------
Github user paul-rogers commented on a diff in the pull request:
https://github.com/apache/drill/pull/839#discussion_r117110883
--- Diff:
contrib/storage-hbase/src/main/java/org/apache/drill/exec/store/hbase/HBaseRecordReader.java
---
@@ -187,8 +189,8 @@ public int next() {
}
int rowCount = 0;
- done:
- for (; rowCount < TARGET_RECORD_COUNT; rowCount++) {
+ // if first row is larger than allowed max size in batch, it will be
added anyway
+ do {
--- End diff --
Still need to monitor row count: row count cannot exceed 64K. So, loop
termination is either exceeds memory limit OR reaches max row count. For row
count, might as well use the original limit, unless we know enough to pick a
better limit.
> Use max allowed allocated memory when defining batch size for hbase record
> reader
> ---------------------------------------------------------------------------------
>
> Key: DRILL-5516
> URL: https://issues.apache.org/jira/browse/DRILL-5516
> Project: Apache Drill
> Issue Type: Improvement
> Components: Storage - HBase
> Affects Versions: 1.10.0
> Reporter: Arina Ielchiieva
> Assignee: Arina Ielchiieva
>
> If early limit 0 optimization is set to true (alter session set
> `planner.enable_limit0_optimization` = true), when executing limit 0 queries
> Drill will return data type from available metadata if possible.
> When Drill can not determine data types from metadata (or if early limit 0
> optimization is set to false), Drill will read first batch of data and
> determine schema.
> Hbase reader determines max batch size using magic number (4000) which can
> lead to OOM when row size is large. The overall vector/batch size issue will
> be reconsidered in future releases.This is temporary fix to avoid OOM.
> Instead of using rows number, we will use max allowed allocated memory which
> will default to 64 mb. If first row in batch is larger than allowed default,
> it will be written in batch but batch will contain only this row.
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