[
https://issues.apache.org/jira/browse/HBASE-18824?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16208781#comment-16208781
]
Xiang Li commented on HBASE-18824:
----------------------------------
Yes, I believe the reason why {{result.size() > count}} is an exception which
should not happen is the max version of Get is set to count
{code:title=HRegion.java|borderStyle=solid}
public void prepareDeleteTimestamps(Mutation mutation, Map<byte[], List<Cell>>
familyMap,
byte[] byteNow) throws IOException {
//...
Get get = new Get(CellUtil.cloneRow(cell));
get.setMaxVersions(count); <-- here
get.addColumn(family, qual);
if (coprocessorHost != null) {
if (!coprocessorHost.prePrepareTimeStampForDeleteVersion(mutation,
cell,
byteNow, get)) {
updateDeleteLatestVersionTimeStamp(cell, get, count, byteNow);
}
} else {
updateDeleteLatestVersionTimeStamp(cell, get, count, byteNow);
}
}
{code}
> Add meaningful comment to HConstants.LATEST_TIMESTAMP to explain why it is
> MAX_VALUE
> ------------------------------------------------------------------------------------
>
> Key: HBASE-18824
> URL: https://issues.apache.org/jira/browse/HBASE-18824
> Project: HBase
> Issue Type: Improvement
> Reporter: Xiang Li
> Assignee: Xiang Li
> Priority: Minor
> Attachments: HBASE-18824.master.000.patch,
> HBASE-18824.master.001.patch, HBASE-18824.master.002.patch
>
>
> Thanks to [Jerry and Chia-Ping Tsai's
> comments|https://issues.apache.org/jira/browse/HBASE-18824?focusedCommentId=16167392&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16167392]
> to correct my wrong understanding.
> The following documentation says that by default(when the timestamp is not
> specified for Put or Delete), system uses the server's {{currentTimeMillis}}.
> 1. In chapter 27.2.4 Put
> bq. Doing a put always creates a new version of a cell, at a certain
> timestamp. {color:#205081}By default the system uses the server’s
> currentTimeMillis{color}, ...
> 2. In chapter 27.2.5 Delete
> bq. Deletes work by creating tombstone markers. For example, let’s suppose we
> want to delete a row. For this you can specify a version, or else
> {color:#205081}by default the currentTimeMillis is used.{color}...
> It seems not consistent with the code. Because in the client side's code,
> when timestamp is not specified, HConstants.LATEST_TIMESTAMP is used, which
> is Long.MAX_VALUE, rather than {{System.currentTimeMillis()}}.
> However, the documentation is correct, because on the server side, timestamp
> of Put cell with HConstants.LATEST_TIMESTAMP will be replaced with server's
> {{currentTimeMillis}}.
> So we decide to add more comments to HConstants.LATEST_TIMESTAMP to help the
> new comers steer clear of the confusion.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
