[LU-7236] OST connect and disconnect on demand

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.12.0
• Labels: OSJ
• Assignee: Alex Zhuravlev
• Reporter: Alex Zhuravlev

Description

currently Lustre client establishes connections to all targets at mount and tries to keep them alive all the time. at big scale this can lead to lots of extra work at mount, failover.

Issue Links

• is blocked by: LU-10018 MDT as a statfs proxy
• is related to: LU-14335 sanity test_812b: can't put import into IDLE state after 40 sec, have FULL
• is related to: LU-11518 lock_count is exceeding lru_size
• is related to: LU-11951 sanity: test_231a failure, idle disconnect & import generation disagreement
• is related to: LU-12328 FLR mirroring on 2.12.1-1 not usable if OST is down
• is related to: LU-12799 NULL pointer dereference IP: ptlrpc_disconnect_and_idle_import
• is related to: LU-9660 reduce ptlrpcd wakeups on idle system
• is related to: LU-11126 replay-single test 89: import.c:1668:ptlrpc_disconnect_idle_interpret()) ASSERTION( imp->imp_state == LUSTRE_IMP_CONNECTING ) failed:
• is related to: LU-11128 replay-single test timeout
• is related to: LU-11206 recovery-mds-scale test failover_ost fails with 'import is not in FULL state'
• is related to: LU-12759 parameter grant_shrink gets reset to 1 after client reconnects
• is related to: LU-12857 recovery-mds-scale test_failover_ost fails with “import is not in FULL state”
• is related to: LU-12364 idle disconnect shouldn't set IDLE going to reconnect
• is related to: LU-5703 Quiesce client mountpoints from the server
• is related to: LU-18015 DNE: client-MDT idle disconnection
• is related to: LU-9441 Use kernel threads in predictable fashion to confine OS noise
• is related to: LU-9555 "df /path/to/project" should return projid-specific values
• is related to: LU-11405 add a test for idle connection feature