> On Dec. 27, 2016, 4:19 p.m., Stephan Erb wrote: > > api/src/main/thrift/org/apache/aurora/gen/storage.thrift, lines 156-157 > > <https://reviews.apache.org/r/54883/diff/2/?file=1591086#file1591086line156> > > > > Is it somehow necessary to use a serialized position here? I have the > > gut feeling that a plain long would probably be better as it reduces > > coupling to replicated log interna.
Actually, this way reduces coupling to the Mesos log. After all, it's an implementation detail of the Mesos replicated log that it uses longs for ordering. In other implementations of distributed logs you might need a tuple as the id - e.g. with BookKeeper, you have a ledger id and sequence id. Whoever wrote the Mesos code (identity is the only public method to get at the underlying value) and our log code (Position is an empty interface) did a good job with the abstractions there. - David ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/54883/#review160165 ----------------------------------------------------------- On Dec. 22, 2016, 9:26 a.m., David McLaughlin wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/54883/ > ----------------------------------------------------------- > > (Updated Dec. 22, 2016, 9:26 a.m.) > > > Review request for Aurora, Joshua Cohen, John Sirois, Santhosh Kumar > Shanmugham, and Zameer Manji. > > > Repository: aurora > > > Description > ------- > > See here for more details: > https://docs.google.com/document/d/1QVSEfeoCyt2D6cCmTCxy8-epufcuzIfnqRUkyT1betY/edit?usp=sharing > > The motivation for this patch is the realisation that if we store Snapshots > outside of the main transaction log, we only ever to need to hold the storage > lock during snapshot creation. This would reduce the time writes are blocked > during snapshots by 80% for a large production cluster. I'm also doing this > with a view to future work, which is described in the document above. > > As long as everything works fine, this change is as simple as adding two new > args to the scheduler JVM. But it's worth noting that once this change is > deployed and the first snapshot is written, you will no longer be able to > rollback without first restoring from a backup. > > > Diffs > ----- > > api/src/main/thrift/org/apache/aurora/gen/storage.thrift > 9e4213f13255a182df938bea44ca87fa03a25318 > examples/vagrant/aurorabuild.sh dbec54d3e677db8cb0f02849e5373e619629fc7c > examples/vagrant/upstart/aurora-scheduler.conf > e68a801017ae02e0ed581129e12a645ccc1e35d4 > src/main/java/org/apache/aurora/scheduler/app/SchedulerMain.java > 43cc5b4645bc26b0fc6b23726ad3292699048ded > src/main/java/org/apache/aurora/scheduler/log/Log.java > dc77eb435e5f8fdce56727a2f679e8e1907e977c > src/main/java/org/apache/aurora/scheduler/log/mesos/DualLogModule.java > PRE-CREATION > src/main/java/org/apache/aurora/scheduler/log/mesos/MesosLog.java > 21855e184fe20dc339713978b32344b6950701ec > > src/main/java/org/apache/aurora/scheduler/log/mesos/MesosLogStreamModule.java > 6704a328a4023a178ed8f86ae4772cb04eb2fa8e > src/main/java/org/apache/aurora/scheduler/storage/log/LogManager.java > cfa9c56c909bac2e885e33a9fe772cb41cbd9fa9 > src/main/java/org/apache/aurora/scheduler/storage/log/LogStorage.java > 387350c7667a5fb8ee674ad0d3dd17529232b25b > > src/main/java/org/apache/aurora/scheduler/storage/log/SnapshotDeduplicator.java > 9733ffe74b107f336858657550156ddb1f1dd215 > src/main/java/org/apache/aurora/scheduler/storage/log/StreamManager.java > ea147c0ba6aaa6d113144be0a8330bd2f73d2453 > > src/main/java/org/apache/aurora/scheduler/storage/log/StreamManagerImpl.java > baf2647c54f1f9918139584e5151873a3853e83c > src/test/java/org/apache/aurora/scheduler/app/SchedulerIT.java > 29a3b4a57925f31e59a49d4bfa630e724cadcb04 > src/test/java/org/apache/aurora/scheduler/log/mesos/MesosLogTest.java > f142f545799d64f9352b0ac6c51942eedf5e9ced > src/test/java/org/apache/aurora/scheduler/storage/log/LogManagerTest.java > 3f445595a81a5655c6c486791a9b55d8dc7f2f76 > src/test/java/org/apache/aurora/scheduler/storage/log/LogStorageTest.java > 34c24aac9339e59c435925bd2357ce86998f5f02 > > Diff: https://reviews.apache.org/r/54883/diff/ > > > Testing > ------- > > I currently have only tested this on one node (wrote this code on a flight). > Will have to verify this in our test clusters before shipping. > > > Example log output on my vagrant image: > > I1222 07:18:36.471 [qtp1117266705-37, LoggingInterceptor] snapshot() > I1222 07:18:36.479 [qtp1117266705-37, LogStorage] Creating snapshot at > position: Position 6 > I1222 07:18:36.485 [qtp1117266705-37, SnapshotStoreImpl] Saving dbsnapshot > I1222 07:18:36.591 [qtp1117266705-37, LogStorage] Write lock released. > I1222 07:18:36.591 [pool-12-thread-1, LogStorage] Persisting snapshot. > I1222 07:18:36.592 [pool-12-thread-1, > SnapshotDeduplicator$SnapshotDeduplicatorImpl] Starting deduplication of a > snapshot with 0 tasks. > I1222 07:18:36.595 [pool-12-thread-1, > SnapshotDeduplicator$SnapshotDeduplicatorImpl] Finished deduplicating > snapshot. Deduplication ratio: 0/0 = NaN%. > I1222 07:18:36.599218 4155 log.cpp:577] Attempting to append 6261 bytes to > the log > I1222 07:18:36.599321 4155 coordinator.cpp:348] Coordinator attempting to > write APPEND action at position 5 > I1222 07:18:36.599573 4160 replica.cpp:537] Replica received write request > for position 5 from (11)@192.168.33.7:8083 > I1222 07:18:36.600693 4160 leveldb.cpp:341] Persisting action (6280 bytes) > to leveldb took 1.061504ms > I1222 07:18:36.600733 4160 replica.cpp:712] Persisted action at 5 > I1222 07:18:36.600844 4160 replica.cpp:691] Replica received learned notice > for position 5 from @0.0.0.0:0 > I1222 07:18:36.601541 4160 leveldb.cpp:341] Persisting action (6282 bytes) > to leveldb took 619657ns > I1222 07:18:36.601569 4160 replica.cpp:712] Persisted action at 5 > I1222 07:18:36.601582 4160 replica.cpp:697] Replica learned APPEND action at > position 5 > I1222 07:18:36.603044 4160 log.cpp:596] Attempting to truncate the log to 5 > I1222 07:18:36.603173 4160 coordinator.cpp:348] Coordinator attempting to > write TRUNCATE action at position 6 > I1222 07:18:36.603330 4160 replica.cpp:537] Replica received write request > for position 6 from (12)@192.168.33.7:8083 > I1222 07:18:36.603890 4160 leveldb.cpp:341] Persisting action (16 bytes) to > leveldb took 502063ns > I1222 07:18:36.603919 4160 replica.cpp:712] Persisted action at 6 > I1222 07:18:36.603991 4160 replica.cpp:691] Replica received learned notice > for position 6 from @0.0.0.0:0 > I1222 07:18:36.604279 4160 leveldb.cpp:341] Persisting action (18 bytes) to > leveldb took 217834ns > I1222 07:18:36.604357 4160 leveldb.cpp:399] Deleting ~3 keys from leveldb > took 13629ns > I1222 07:18:36.604372 4160 replica.cpp:712] Persisted action at 6 > I1222 07:18:36.604383 4160 replica.cpp:697] Replica learned TRUNCATE action > at position 6 > I1222 07:18:36.604581 4160 log.cpp:596] Attempting to truncate the log to 6 > I1222 07:18:36.604682 4160 coordinator.cpp:348] Coordinator attempting to > write TRUNCATE action at position 7 > I1222 07:18:36.604778 4160 replica.cpp:537] Replica received write request > for position 7 from (13)@192.168.33.7:8083 > I1222 07:18:36.605317 4160 leveldb.cpp:341] Persisting action (16 bytes) to > leveldb took 485544ns > I1222 07:18:36.605356 4160 replica.cpp:712] Persisted action at 7 > I1222 07:18:36.605439 4160 replica.cpp:691] Replica received learned notice > for position 7 from @0.0.0.0:0 > I1222 07:18:36.605736 4160 leveldb.cpp:341] Persisting action (18 bytes) to > leveldb took 215503ns > I1222 07:18:36.605773 4160 leveldb.cpp:399] Deleting ~3 keys from leveldb > took 9620ns > I1222 07:18:36.605787 4160 replica.cpp:712] Persisted action at 7 > I1222 07:18:36.605798 4160 replica.cpp:697] Replica learned TRUNCATE action > at position 7 > I1222 07:18:36.605 [pool-12-thread-1, LogStorage] Snapshot complete. host > attrs: 1, cron jobs: 0, locks: 0, quota confs: 0, tasks: 0, updates: 0 > > > Thanks, > > David McLaughlin > >
