This patch fixes a possible bug, reproduced rarely only seen
once.
```
panic: runtime error: index out of range
goroutine 136 [running]:
panic(0xac1a40, 0xc4200120b0)
/usr/local/go/src/runtime/panic.go:500 +0x1a1
github.com/minio/minio/vendor/github.com/minio/dsync.lock.func1(0xc4203d2240, 0x4, 0xc420474080, 0x4, 0x4, 0xc4202abb60, 0x0, 0xa86d01, 0xefcfc0, 0xc420417a80)
/go/src/github.com/minio/minio/vendor/github.com/minio/dsync/drwmutex.go:170 +0x69b
created by github.com/minio/minio/vendor/github.com/minio/dsync.lock
/go/src/github.com/minio/minio/vendor/github.com/minio/dsync/drwmutex.go:191 +0xf4
```
- abstract out instrumentation information.
- use separate lockInstance type that encapsulates the nsMutex, volume,
path and opsID as the frontend or top-level lock object.
For command line arguments we are currently following
- <node-1>:/path ... <node-n>:/path
This patch changes this to
- http://<node-1>/path ... http://<node-n>/path
Added clear subcommand for control lock with following options:
```
3. Clear lock named 'bucket/object' (exact match).
$ minio control lock clear http://localhost:9000/bucket/object
4. Clear all locks with names that start with 'bucket/prefix' (wildcard match).
$ minio control lock --recursive clear http://localhost:9000/bucket/prefix
5. Clear all locks older than 10minutes.
$ minio control lock --older-than=10m clear http://localhost:9000/
6. Clear all locks with names that start with 'bucket/a' and that are older than 1hour.
$ minio control lock --recursive --older-than=1h clear http://localhost:9000/bucket/a
```
These messages based on our prep stage during XL
and prints more informative message regarding
drive information.
This change also does a much needed refactoring.
- Instrumentation for locks.
- Detailed test coverage.
- Adding RPC control handler to fetch lock instrumentation.
- RPC control handlers suite tests with a test RPC server.
This PR contains various fixes for the distributed release:
- Use DRWMutex in namespace-lock only for a single Lock()/RLock() call in conformance to server-side rw-locking as implemented in minio/dsync
- Implement missing cases in lock-rpc-server to catch Unlock() for active read locks and RUnlock() for an active write lock
- Refactor RPCClient to release local mutex while making actual RPC.Call()
This patch brings in the removal of debug logging altogether, instead
we bring in the functionality of being able to trace the errors properly
pointing back to the origination of the problem.
To enable tracing you need to enable "MINIO_TRACE" set to "1" or "true"
environment variable which would print back traces whenever there is an
error which is unhandled or at the handler layer.
By default this tracing is turned off and only user level logging is
provided.
Harshavardhana