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Sean Busbey commented on HBASE-12219: ------------------------------------- Can you update the patch to be based on master? It looks like the same NN reading code is in the cache there. > Cache more efficiently getAll() and get() in FSTableDescriptors > --------------------------------------------------------------- > > Key: HBASE-12219 > URL: https://issues.apache.org/jira/browse/HBASE-12219 > Project: HBase > Issue Type: Bug > Components: master > Affects Versions: 0.94.24, 0.99.1, 0.98.6.1 > Reporter: Esteban Gutierrez > Assignee: Esteban Gutierrez > Labels: scalability > Attachments: HBASE-12219.v0.txt, list.png > > > Currently table descriptors and tables are cached once they are accessed for > the first time. Next calls to the master only require a trip to HDFS to > lookup the modified time in order to reload the table descriptors if > modified. However in clusters with a large number of tables or concurrent > clients and this can be too aggressive to HDFS and the master causing > contention to process other requests. A simple solution is to have a TTL > based cached for FSTableDescriptors#getAll() and > FSTableDescriptors#TableDescriptorAndModtime() that can allow the master to > process those calls faster without causing contention without having to > perform a trip to HDFS for every call. to listtables() or getTableDescriptor() -- This message was sent by Atlassian JIRA (v6.3.4#6332)