When healing is parallelized by setting the ` _MINIO_HEAL_WORKERS`
environment variable, multiple goroutines may race while updating the disk's
healing tracker. This change serializes only these concurrent updates using a
channel. Note, the healing tracker is still not concurrency safe in other contexts.
Directories markers are not healed when healing a new fresh disk. A
a proper fix would be moving object names encoding/decoding to erasure
object level but it is too late now since the object to set distribution is
calculated at a higher level.
- Always reformat all disks when a new disk is detected, this will
ensure new uploads to be written in new fresh disks
- Always heal all buckets first when an erasure set started to be healed
- Use a lock to prevent two disks belonging to different nodes but in
the same erasure set to be healed in parallel
- Heal different sets in parallel
Bonus:
- Avoid logging errUnformattedDisk when a new fresh disk is inserted but
not detected by healing mechanism yet (10 seconds lag)
Main motivation is move towards a common backend format
for all different types of modes in MinIO, allowing for
a simpler code and predictable behavior across all features.
This PR also brings features such as versioning, replication,
transitioning to single drive setups.
listing can fail and it is allowed to be retried,
instead of returning right away return an error at
the end - heal the rest of the buckets and objects,
and when we are retrying skip the buckets that
are already marked done by using the tracked buckets.
fixes#12972
Faster healing as well as making healing more
responsive for faster scanner times.
also fixes a bug introduced in #13079, newly replaced
disks were not healing automatically.
- 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.
proceed to heal the cluster when all the
drives in a set have failed, this is extremely
rare occurrence but even if it happens we allow
the cluster to be functional.
`mc admin heal` command will show servers/disks tolerance, for that
purpose, you need to know the number of parity disks for each storage
class.
Parity is always the same in all pools.
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.
backend-encrypted doesn't need to be explicitly healed anymore
since this file is deleted upon upgrade and migration to the
KMS based encrypted config/IAM credentials.
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
* Provide information on *actively* healing, buckets healed/queued, objects healed/failed.
* Add concurrent healing of multiple sets (typically on startup).
* Add bucket level resume, so restarts will only heal non-healed buckets.
* Print summary after healing a disk is done.
Previously we added heal trigger when bit-rot checks
failed, now extend that to support heal when parts
are not found either. This healing gets only triggered
if we can successfully decode the object i.e read
quorum is still satisfied for the object.
If an erasure set had a drive replacement recently, we don't
need to attempt healing on another drive with in the same erasure
set - this would ensure we do not double heal the same content
and also prioritizes usage for such an erasure set to be calculated
sooner.
Optimizations include
- do not write the metacache block if the size of the
block is '0' and it is the first block - where listing
is attempted for a transient prefix, this helps to
avoid creating lots of empty metacache entries for
`minioMetaBucket`
- avoid the entire initialization sequence of cacheCh
, metacacheBlockWriter if we are simply going to skip
them when discardResults is set to true.
- No need to hold write locks while writing metacache
blocks - each block is unique, per bucket, per prefix
and also is written by a single node.
optimization mainly to avoid listing the entire
`.minio.sys/buckets/.minio.sys` directory, this
can get really huge and comes in the way of startup
routines, contents inside `.minio.sys/buckets/.minio.sys`
are rather transient and not necessary to be healed.
supports `mc admin config set <alias> heal sleep=100ms` to
enable more aggressive healing under certain times.
also optimize some areas that were doing extra checks than
necessary when bitrotscan was enabled, avoid double sleeps
make healing more predictable.
fixes#10497
reference format should be source of truth
for inconsistent drives which reconnect,
add them back to their original position
remove automatic fix for existing offline
disk uuids
`mc admin info` on busy setups will not move HDD
heads unnecessarily for repeated calls, provides
a better responsiveness for the call overall.
Bonus change allow listTolerancePerSet be N-1
for good entries, to avoid skipping entries
for some reason one of the disk went offline.
It is possible the heal drives are not reported from
the maintenance check because the background heal
state simply relied on the `format.json` for capturing
unformatted drives. It is possible that drives might
be still healing - make sure that applications which
rely on cluster health check respond back this detail.
Also, revamp the way ListBuckets work make few portions
of the healing logic parallel
- walk objects for healing disks in parallel
- collect the list of buckets in parallel across drives
- provide consistent view for listBuckets()
* Fix cases where minimum timeout > default timeout.
* Add defensive code for too small/negative timeouts.
* Never set timeout below the maximum value of a request.
* Protect against (unlikely) int64 wraps.
* Decrease timeout slower.
* Don't re-lock before copying.
inconsistent drive healing when one of the drive is offline
while a new drive was replaced, this change is to ensure
that we can add the offline drive back into the mix by
healing it again.
Add context to all (non-trivial) calls to the storage layer.
Contexts are propagated through the REST client.
- `context.TODO()` is left in place for the places where it needs to be added to the caller.
- `endWalkCh` could probably be removed from the walkers, but no changes so far.
The "dangerous" part is that now a caller disconnecting *will* propagate down, so a
"delete" operation will now be interrupted. In some cases we might want to disconnect
this functionality so the operation completes if it has started, leaving the system in a cleaner state.
We can reduce this further in the future, but this is a good
value to keep around. With the advent of continuous healing,
we can be assured that namespace will eventually be
consistent so we are okay to avoid the necessity to
a list across all drives on all sets.
Bonus Pop()'s in parallel seem to have the potential to
wait too on large drive setups and cause more slowness
instead of gaining any performance remove it for now.
Also, implement load balanced reply for local disks,
ensuring that local disks have an affinity for
- cleanupStaleMultipartUploads()
bonus make sure to ignore objectNotFound, and versionNotFound
errors properly at all layers, since HealObjects() returns
objectNotFound error if the bucket or prefix is empty.
Krishnan Parthasarathi
ebozduman
Harshavardhana
Anis Elleuch
jiangfucheng
AlexHuang2021
Klaus Post