[HBASE-12219] Cache more efficiently getAll() and get() in FSTableDescriptors

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.94.24, 0.99.1, 0.98.6.1
• Fix Version/s: 0.98.8, 0.99.2
• Component/s: master
• Labels: scalability
• Hadoop Flags: Reviewed
• Assignee: Esteban Gutierrez
• Reporter: Esteban Gutierrez
• Created: 09/Oct/14 19:31
• Updated: 06/Apr/18 17:55
• Resolved: 05/Nov/14 00:17

Description

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()

Issue Links

• links to: r/26878