This change makes the etcd package compatible with the existing Go
ecosystem for module versioning.
Used this tool to update package imports:
https://github.com/KSubedi/gomove
TryLock locks the mutex if not already locked by another session.
If lock is held by another session, return immediately after attempting necessary cleanup
Added integration test
Fixes#10493
Update to Go 1.12.5 testing. Remove deprecated unused and gosimple
pacakges, and mask staticcheck 1006. Also, fix unconvert errors related
to unnecessary type conversions and following staticcheck errors:
- remove redundant return statements
- use for range instead of for select
- use time.Since instead of time.Now().Sub
- omit comparison to bool constant
- replace T.Fatal and T.Fatalf in tests with T.Error and T.Fatalf respectively because the goroutine calls T.Fatal must be called in the same goroutine as the test
- fix error strings that should not be capitalized
- use sort.Strings(...) instead of sort.Sort(sort.StringSlice(...))
- use he status code of Canceled instead of grpc.ErrClientConnClosing which is deprecated
- use use status.Errorf instead of grpc.Errorf which is deprecated
Related #10528#10438
Convenient invariant:
- if werr == nil then lock is supposed to be locked at the moment.
While we could not be confident in stronger invariant ('is exactly locked'),
it were inconvenient that previous code could return `werr == nil` after
Mutex.Unlock.
It could happen when ctx is canceled/timeouted exactly after waitDeletes
successfully returned werr == nil and before `<-ctx.Done()` checked.
While such situation is very rare, it is still possible.
fixes#10111
Default stm isolation level is serializable snapshot isolation, which
is different than snapshot isolation (SI)
Signed-off-by: Hui Kang <kangh@us.ibm.com>
The uncontended path for a mutex would fetch the minimum
revision key on the prefix after creating its entry in
the wait list. This fetch can be rolled into the txn for
creating the wait key, eliminating a round-trip for immediately
acquiring the lock.
Watching from the leader's ModRevision could cause live-locking on
observe retry loops when the ModRevision is less than the compacted
revision. Instead, start watching the leader from at least the store
revision of the linearized read used to detect the current leader.
Fixes#7815
Pure Snapshot isolation would permit read conflicts. Change the name
from Snapshot to SerializableSnapshot to reflect that it will also
reject read conflicts.
The Get for the leader key will fetch based on the latest revision
instead of the deletion revision, missing leader updates between
the delete and the Get.
Although it's usually safe to skip these updates since they're
stale, it makes testing more difficult and in some cases the
full leader update history is desirable.
Addresses a case where two clients share the same lease. A client resigns but
disconnects / crashes and doesn't realize it. Another client reuses the
lease and gets leadership with a new key. The old client comes back and
tries to resign again, revoking the new leadership of the new client.
The full information about the leader's key is necessary to
safely use elections with transactions. Instead of returning
only the value on Leader(), return the entire GetResposne.
This change is needed to handle process restarts with elections. When the
leader process is restarted, it should be able to hang on to the leadership
by using the existing lease.
Fixes#7166
Piotr Tabor