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From "Adam J Shook (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-4751) Some WALs don't replicate due to lacking a createdTime entry
Date Mon, 04 Dec 2017 17:54:00 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-4751?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16277154#comment-16277154
] 

Adam J Shook commented on ACCUMULO-4751:
----------------------------------------

My initial finding is that some entries coming out of the {{StatusUtil}} don't have a {{createdTime}}.
 Whereas something like [1] writes a metadata entry to a WAL and the replication status is
updated with a {{createdTime}}.  I am guessing that, in this case, there is no ingest for
a particular table during the lifetime of the WAL, so the work to replicate the WAL to a particular
table (via the key extent) is never created.  However, something else is writing some information
that doesn't have a {{createdTime}}.

I'll do some more digging to see if this can be nailed down.

[1] https://github.com/apache/accumulo/blob/rel/1.8.1/server/tserver/src/main/java/org/apache/accumulo/tserver/log/TabletServerLogger.java#L390

> Some WALs don't replicate due to lacking a createdTime entry
> ------------------------------------------------------------
>
>                 Key: ACCUMULO-4751
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-4751
>             Project: Accumulo
>          Issue Type: Bug
>    Affects Versions: 1.7.3, 1.8.1
>            Reporter: Adam J Shook
>            Assignee: Adam J Shook
>
> From what I can tell, the below error is thrown when no data for a particular table is
written to a WAL, but the file is closed.  This would be because the {{Status}} entry from
the {{StatusUtil}} for {{fileClosed}} is pre-built and therefore does not have a {{createdTime}}.
 This prevents a WAL from being replicated until a {{createdTime}} entry is added manually.
> From the Accumulo master:
> {code}
> Status record ([begin: 0 end: 0 infiniteEnd: true closed: true]) for hdfs://namenode:9000/accumulo/wal/tserver.example.com+31732/f922df9c-3ffc-49ee-8d0c-261c7a05fea2
in table 7l was written to metadata table which lacked createdTime
> {code}
> There are two solutions I have in mind:
> 1. Update the {{StatusUtil}} such that every returned {{Status}} object sets the {{createdTime}}
to {{System.currentTimeMillis}} if not explicitly given.
> 2. Update the Accumulo Master to set the {{createdTime}} to the WAL's modification time
in HDFS if the WAL is closed but there is no {{createdTime}}.



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