[
https://issues.apache.org/jira/browse/HBASE-4485?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13127696#comment-13127696
]
Ted Yu commented on HBASE-4485:
-------------------------------
Here is the related change w.r.t. ignoreNewerKVs():
{code}
Index: src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java
===================================================================
--- src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java
(revision 1176657)
+++ src/main/java/org/apache/hadoop/hbase/regionserver/ScanQueryMatcher.java
(working copy)
@@ -59,6 +59,12 @@
/** Row the query is on */
protected byte [] row;
+ /** Should we ignore KV's with a newer RWCC timestamp **/
+ private boolean ignoreNewerKVs = false;
+ public void ignoreNewerKVs() {
+ this.ignoreNewerKVs = true;
+ }
+
/**
* Constructs a ScanQueryMatcher for a Scan.
* @param scan
@@ -166,6 +172,12 @@
return columns.getNextRowOrNextColumn(bytes, offset, qualLength);
}
+ // The compaction thread has no readPoint set. For other operations, we
+ // will ignore updates that are done after the read operation has started.
+ if (this.ignoreNewerKVs &&
+ kv.getMemstoreTS() > ReadWriteConsistencyControl.getThreadReadPoint())
+ return MatchCode.SKIP;
+
byte type = kv.getType();
if (isDelete(type)) {
if (tr.withinOrAfterTimeRange(timestamp)) {
{code}
> Eliminate window of missing Data
> --------------------------------
>
> Key: HBASE-4485
> URL: https://issues.apache.org/jira/browse/HBASE-4485
> Project: HBase
> Issue Type: Sub-task
> Reporter: Amitanand Aiyer
> Assignee: Amitanand Aiyer
> Fix For: 0.94.0
>
> Attachments: 4485-v1.diff, 4485-v2.diff, 4485-v3.diff, 4485-v4.diff,
> repro_bug-4485.diff
>
>
> After incorporating v11 of the 2856 fix, we discovered that we are still
> having some ACID violations.
> This time, however, the problem is not about including "newer" updates; but,
> about missing older updates
> that should be including.
> Here is what seems to be happening.
> There is a race condition in the StoreScanner.getScanners()
> private List<KeyValueScanner> getScanners(Scan scan,
> final NavigableSet<byte[]> columns) throws IOException {
> // First the store file scanners
> List<StoreFileScanner> sfScanners = StoreFileScanner
> .getScannersForStoreFiles(store.getStorefiles(), cacheBlocks,
> isGet, false);
> List<KeyValueScanner> scanners =
> new ArrayList<KeyValueScanner>(sfScanners.size()+1);
> // include only those scan files which pass all filters
> for (StoreFileScanner sfs : sfScanners) {
> if (sfs.shouldSeek(scan, columns)) {
> scanners.add(sfs);
> }
> }
> // Then the memstore scanners
> if (this.store.memstore.shouldSeek(scan)) {
> scanners.addAll(this.store.memstore.getScanners());
> }
> return scanners;
> }
> If for example there is a call to Store.updateStorefiles() that happens
> between
> the store.getStorefiles() and this.store.memstore.getScanners(); then
> it is possible that there was a new HFile created, that is not seen by the
> StoreScanner, and the data is not present in the Memstore.snapshot either.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
