* regenerate master_grpc.pb.go with protoc-gen-go-grpc v1.6.2
The other generated pb files are already on v1.6.2; this one was stale.
* shell: keep unlock from racing the lease renewal
A renewal RPC in flight while ReleaseLock runs re-creates the lock on the
master after the release deletes it, and can blank the client name if the
renewal reads it mid-release. The stale-token release is then ignored, so
the lock stays held (sometimes anonymously) until it expires. Serialize
the renew and release RPCs, and set the client name before flipping
isLocked so the renewal never sends a partial acquisition.
* shell: restart lease renewal after a failed renewal
The renewal goroutine exits on error but never cleared its running flag,
so later locks in the same process were never renewed and silently
expired after ten seconds.
* shell: show who holds the cluster lock
A blocked lock command gave no hint that another client holds the lock
(the refusals only surfaced at -v=2), and cluster.status reported the
shell's own lock state as if it were the cluster's. Add a
GetAdminLockStatus RPC to the master so lock prints the holder before
blocking and cluster.status shows the actual cluster-wide holder. Both
degrade silently against masters without the RPC.
* shell: bound admin lock RPC attempts with timeouts
The lease, renew, release, and holder-status calls all ran without a
deadline, so an unresponsive master could hang the renewal goroutine,
an unlock (which now waits on the renewal mutex), or the shell prompt.
Give each attempt its own short context; the retry loops still resolve
a fresh leader on the next try.
* master: reject admin token release on non-leaders
A follower holds no lock state, so it answered a release with success
while the leader kept the lock until expiry. Refuse like LeaseAdminToken
does so the client can try the leader instead.
* shell: leave the lock release call unbounded
A release cut short by a deadline leaves the lock held on the master
until it expires, so a slow master would turn every unlock into a
ten-second ghost lock. Restore the single fire-and-forget attempt;
the timeouts stay on the lease and renew paths, where a stalled call
forfeits the lease anyway.
* shell: release only the token unlock started with
A RequestLock racing a slow release (the admin presence lock does this
on shutdown) could have its freshly acquired token sent in the release
request or zeroed by the trailing stores. Capture the token once under
the mutex and compare on clear so a concurrent acquisition survives an
in-flight unlock.
Chris Lu
564803becd