Refresh was doing a linear scan of all locked resources. This was adding
up to significant delays in locking on high load systems with long
running requests.
Add a secondary index for O(log(n)) UID -> resource lookups.
Multiple resources are stored in consecutive strings.
Bonus fixes:
* On multiple Unlock entries unlock the write locks we can.
* Fix `expireOldLocks` skipping checks on entry after expiring one.
* Return fast on canTakeUnlock/canTakeLock.
* Prealloc some places.
it would seem like using `bufio.Scan()` is very
slow for heavy concurrent I/O, ie. when r.Body
is slow , instead use a proper
binary exchange format, to marshal and unmarshal
the LockArgs datastructure in a cleaner way.
this PR increases performance of the locking
sub-system for tiny repeated read lock requests
on same object.
```
BenchmarkLockArgs
BenchmarkLockArgs-4 6417609 185.7 ns/op 56 B/op 2 allocs/op
BenchmarkLockArgsOld
BenchmarkLockArgsOld-4 1187368 1015 ns/op 4096 B/op 1 allocs/op
```
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`
using isServerResolvable for expiration can lead to chicken
and egg problems, a lock might expire knowingly when server
is booting up causing perpetual locks getting expired.
- lock maintenance loop was incorrectly sleeping
as well as using ticker badly, leading to
extra expiration routines getting triggered
that could flood the network.
- multipart upload cleanup should be based on
timer instead of ticker, to ensure that long
running jobs don't get triggered twice.
- make sure to get right lockers for object name
for some flaky networks this may be too fast of a value
choose a defensive value, and let this be addressed
properly in a new refactor of dsync with renewal logic.
Also enable faster fallback delay to cater for misconfigured
IPv6 servers
refer
- https://golang.org/pkg/net/#Dialer
- https://tools.ietf.org/html/rfc6555
This refactor is done for few reasons below
- to avoid deadlocks in scenarios when number
of nodes are smaller < actual erasure stripe
count where in N participating local lockers
can lead to deadlocks across systems.
- avoids expiry routines to run 1000 of separate
network operations and routes per disk where
as each of them are still accessing one single
local entity.
- it is ideal to have since globalLockServer
per instance.
- In a 32node deployment however, each server
group is still concentrated towards the
same set of lockers that partipicate during
the write/read phase, unlike previous minio/dsync
implementation - this potentially avoids send
32 requests instead we will still send at max
requests of unique nodes participating in a
write/read phase.
- reduces overall chattiness on smaller setups.
only newly replaced drives get the new `format.json`,
this avoids disks reloading their in-memory reference
format, ensures that drives are online without
reloading the in-memory reference format.
keeping reference format in-tact means UUIDs
never change once they are formatted.
lockers currently might leave stale lockers,
in unknown ways waiting for downed lockers.
locker check interval is high enough to safely
cleanup stale locks.
This PR fixes a hang which occurs quite commonly at higher concurrency
by allowing following changes
- allowing lower connections in time_wait allows faster socket open's
- lower idle connection timeout to ensure that we let kernel
reclaim the time_wait connections quickly
- increase somaxconn to 4096 instead of 2048 to allow larger tcp
syn backlogs.
fixes#10413
In almost all scenarios MinIO now is
mostly ready for all sub-systems
independently, safe-mode is not useful
anymore and do not serve its original
intended purpose.
allow server to be fully functional
even with config partially configured,
this is to cater for availability of actual
I/O v/s manually fixing the server.
In k8s like environments it will never make
sense to take pod into safe-mode state,
because there is no real access to perform
any remote operation on them.
- Add owner information for expiry, locking, unlocking a resource
- TopLocks returns now locks in quorum by default, provides
a way to capture stale locks as well with `?stale=true`
- Simplify the quorum handling for locks to avoid from storage
class, because there were challenges to make it consistent
across all situations.
- And other tiny simplifications to reset locks.
It is possible in situations when server was deployed
in asymmetric configuration in the past such as
```
minio server ~/fs{1...4}/disk{1...5}
```
Results in setDriveCount of 10 in older releases
but with fairly recent releases we have moved to
having server affinity which means that a set drive
count ascertained from above config will be now '4'
While the object layer make sure that we honor
`format.json` the storageClass configuration however
was by mistake was using the global value obtained
by heuristics. Which leads to prematurely using
lower parity without being requested by the an
administrator.
This PR fixes this behavior.
Context timeout might race on each other when timeouts are lower
i.e when two lock attempts happened very quickly on the same resource
and the servers were yet trying to establish quorum.
This situation can lead to locks held which wouldn't be unlocked
and subsequent lock attempts would fail.
This would require a complete server restart. A potential of this
issue happening is when server is booting up and we are trying
to hold a 'transaction.lock' in quick bursts of timeout.
- Add changes to ensure remote disks are not
incorrectly taken online if their order has
changed or are incorrect disks.
- Bring changes to peer to detect disconnection
with separate Health handler, to avoid a
rather expensive call GetLocakDiskIDs()
- Follow up on the same changes for Lockers
as well
- Implement a new xl.json 2.0.0 format to support,
this moves the entire marshaling logic to POSIX
layer, top layer always consumes a common FileInfo
construct which simplifies the metadata reads.
- Implement list object versions
- Migrate to siphash from crchash for new deployments
for object placements.
Fixes#2111
- acquire since leader lock for all background operations
- healing, crawling and applying lifecycle policies.
- simplify lifecyle to avoid network calls, which was a
bug in implementation - we should hold a leader and
do everything from there, we have access to entire
name space.
- make listing, walking not interfere by slowing itself
down like the crawler.
- effectively use global context everywhere to ensure
proper shutdown, in cache, lifecycle, healing
- don't read `format.json` for prometheus metrics in
StorageInfo() call.
The staleness of a lock should be determined by
the quorum number of entries returning stale,
this allows for situations when locks are held
when nodes are down - we don't accidentally
clear locks unintentionally when they are valid
and correct.
Also lock maintenance should be run by all servers,
not one server, stale locks need to be run outside
the requirement for holding distributed locks.
Thanks @klauspost for reproducing this issue
lock ownership is limited to endpoints on first zone,
as we do not hold locks on other zones in an expanded
setup. current code unintentionally expired active locks
when it couldn't see ownership from the secondary zone
which leads to unexpected bugs as locking fails to work
as expected.
Change distributed locking to allow taking bulk locks
across objects, reduces usually 1000 calls to 1.
Also allows for situations where multiple clients sends
delete requests to objects with following names
```
{1,2,3,4,5}
```
```
{5,4,3,2,1}
```
will block and ensure that we do not fail the request
on each other.
This PR implements locking from a global entity into
a more localized set level entity, allowing for locks
to be held only on the resources which are writing
to a collection of disks rather than a global level.
In this process this PR also removes the top-level
limit of 32 nodes to an unlimited number of nodes. This
is a precursor change before bring in bucket expansion.
This PR adds code to appropriately handle versioning issues
that come up quite constantly across our API changes. Currently
we were also routing our requests wrong which sort of made it
harder to write a consistent error handling code to appropriately
reject or honor requests.
This PR potentially fixes issues
- old mc is used against new minio release which is incompatible
returns an appropriate for client action.
- any older servers talking to each other, report appropriate error
- incompatible peer servers should report error and reject the calls
with appropriate error
The problem in current code was we were removing
an entry from a lock lockerMap without considering
the fact that different entry for same resource is
a possibility due the nature of locks that can be
acquired in parallel before we decide if the lock
is considered stale
A sequence of events is as follows
- Lock("resource")
- lockMaintenance(finds a long lived lock in this "resource")
- Owner node rebooted which now retruns Expired() as true for
this "resource"
- Unlock("resource") which succeeded in quorum
- Now by this time application retried and acquired a new
Lock() on the same "resource"
- Now that we have Expired() true from the previous call,
we proceed to purge the entry from the local lockMap()
local lockMap reports a different entry for the expired
UID which results in a spurious log entry.
This PR removes this logging as this situation is an
expected scenario.
In distributed mode, use REST API to acquire and manage locks instead
of RPC.
RPC has been completely removed from MinIO source.
Since we are moving from RPC to REST, we cannot use rolling upgrades as the
nodes that have not yet been upgraded cannot talk to the ones that have
been upgraded.
We expect all minio processes on all nodes to be stopped and then the
upgrade process to be completed.
Also force http1.1 for inter-node communication
