Bug #41140
Updated by Patrick Donnelly over 4 years ago
Under -create- workloads that result in the acquisition of a lot of capabilities, large create workloads, the MDS can't trim the cache fast enough. The cache trimming throttle gets hit at ~64K dentries removed but because the upkeep trimming only occurs every 5 seconds, the cache is trimmed too slowly. It's undesirable to just increase the throttle limit from 64K to 512K as then the MDS spends a long time trimming the cache every 5 seconds. A better approach would be to drive cache trimming more regularly. See also thread: https://lists.ceph.io/hyperkitty/list/ceph-users@ceph.io/thread/U7XNK3RTV3YZHJFUZ3QJUXHH2WYAT4DN/