instead upon any error in renameData(), we still
preserve the existing dataDir in some form for
recoverability in strange situations such as out
of disk space type errors.
Bonus: avoid running list and heal() instead allow
versions disparity to return the actual versions,
uuid to heal. Currently limit this to 100 versions
and lesser disparate objects.
an undo now reverts back the xl.meta from xl.meta.bkp
during overwrites on such flaky setups.
Bonus: Save N depth syscalls via skipping the parents
upon overwrites and versioned updates.
Flaky setup examples are stretch clusters with regular
packet drops etc, we need to add some defensive code
around to avoid dangling objects.
This PR fixes a bug that perhaps has been long introduced,
with no visible workarounds. In any deployment, if an entire
erasure set is deleted, there is no way the cluster recovers.
there is potential for danglingWrites when quorum failed, where
only some drives took a successful write, generally this is left
to the healing routine to pick it up. However it is better that
we delete it right away to avoid potential for quorum issues on
version signature when there are many versions of an object.
there is a possibility that slow drives can actually add latency
to the overall call, leading to a large spike in latency.
this can happen if there are other parallel listObjects()
calls to the same drive, in-turn causing each other to sort
of serialize.
this potentially improves performance and makes PutObject()
also non-blocking.
One usee reported having mc admin heal status output ETA increasing
by time. It turned out it is MRF that is not clearing its data due to a
bug in the code.
pendingItems is increased when an object is queued to be healed but
never decreasd when there is a healing error. This commit will decrease
pendingItems and pendingBytes even when there is an error to give
accurate reporting.
.Reset() documentation states:
For a Timer created with NewTimer, Reset should be invoked only on stopped
or expired timers with drained channels.
This change is just to comply with this requirement as there might be some
runtime dependent situation that might lead to unexpected behavior.
- remove sourceCh usage from healing
we already have tasks and resp channel
- use read locks to lookup globalHealConfig
- fix healing resolver to pick candidates quickly
that need healing, without this resolver was
unexpectedly skipping.
healObject() should be non-blocking to ensure
that scanner is not blocked for a long time,
this adversely affects performance of the scanner
and also affects the way usage is updated
subsequently.
This PR allows for a non-blocking behavior for
healing, dropping operations that cannot be queued
anymore.
This commit gathers MRF metrics from
all nodes in a cluster and return it to the caller. This will show information about the
number of objects in the MRF queues
waiting to be healed.
