21.7. Directory Operations

In order to improve the performance of directory operations of Red Hat Gluster Storage volumes, the maximum metadata (stat, xattr) caching time on the client side is increased to 10 minutes, without compromising on the consistency of the cache.
Significant performance improvements can be achieved in the following workloads by enabling metadata caching:
  • Listing of directories (recursive)
  • Creating files
  • Deleting files
  • Renaming files

21.7.1. Enabling Metadata Caching

Enable metadata caching to improve the performance of directory operations. Execute the following commands from any one of the nodes on the trusted storage pool in the order mentioned below.

Note

If majority of the workload is modifying the same set of files and directories simultaneously from multiple clients, then enabling metadata caching might not provide the desired performance improvement.
  1. Execute the following command to enable metadata caching and cache invalidation: 
    # gluster volume set <volname> group metadata-cache
    This is group set option which sets multiple volume options in a single command.
  2. To increase the number of files that can be cached, execute the following command: 
    # gluster volume set <VOLNAME> network.inode-lru-limit <n>
    n, is set to 50000. It can be increased if the number of active files in the volume is very high. Increasing this number increases the memory footprint of the brick processes.