GitHub user selvaganesang opened a pull request:
https://github.com/apache/trafodion/pull/1612
[TRAFODION-3110] Refactor LOB access to use the new implementation ofâ¦
⦠HdfsClient
This feature is enabled by default. To disable, set a variable
USE_LIBHDFS=1 in
$TRAF_HOME/etc/ms.env and restart the trafodion cluster.
This feature includes the following:
1. Uses single FSDataInputStream for each LOB column in a query as
opposed to the opening the hdfs file for every row.
2. Uses FSDataOutputStream to write the lob data but closes it
immediately to allow concurrent writes to the hdfs file. HDFS supports
a single writer at a time. Need to conform if multiple writes can
be done without the need for RMS lock feature.
3. Improved error messaging that displays the java exception stack to the
end user.
4. LOB worker threads are no longer created
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/selvaganesang/trafodion trafodion_2917_1
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/trafodion/pull/1612.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #1612
----
commit 52f074af0e866fe82ea4f37eaf90cdc880871851
Author: selvaganesang <selva.govindarajan@...>
Date: 2018-06-15T22:53:04Z
[TRAFODION-3110] Refactor LOB access to use the new implementation of
HdfsClient
This feature is enabled by default. To disable, set a variable
USE_LIBHDFS=1 in
$TRAF_HOME/etc/ms.env and restart the trafodion cluster.
This feature includes the following:
1. Uses single FSDataInputStream for each LOB column in a query as
opposed to the opening the hdfs file for every row.
2. Uses FSDataOutputStream to write the lob data but closes it
immediately to allow concurrent writes to the hdfs file. HDFS supports
a single writer at a time. Need to conform if multiple writes can
be done without the need for RMS lock feature.
3. Improved error messaging that displays the java exception stack to the
end user.
4. LOB worker threads are no longer created
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