ModifyTableProcedure is using MoveRegionProcedure in a way
that was unintended from the original implementation. As such,
we have to guard against certain usages of it. We know we can
re-open OPEN regions, but regions in OPENING will similarly
soon be OPEN (thus, we want to reopen those regions too).
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: zhangduo <zhangduo@apache.org>
* modify the jar checking script to take args; make hadoop stuff optional
* separate out checking the artifacts that have hadoop vs those that don't.
* * Unfortunately means we need two modules for checking things
* * put in a safety check that the support script for checking jar contents is maintained in both modules
* * have to carve out an exception for o.a.hadoop.metrics2. :(
* fix duplicated class warning
* clean up dependencies in hbase-server and some modules that depend on it.
* allow Hadoop to have its own htrace where it needs it
* add a precommit check to make sure we're not using old htrace imports
Conflicts:
hbase-backup/pom.xml
hbase-checkstyle/src/main/resources/hbase/checkstyle-suppressions.xml
Signed-off-by: Mike Drob <mdrob@apache.org>
Cannot go to latest (8.9) yet due to
https://github.com/checkstyle/checkstyle/issues/5279
* move hbaseanti import checks to checkstyle
* implment a few missing equals checks, and ignore one
* fix lots of javadoc errors
Signed-off-by: Sean Busbey <busbey@apache.org>
A reattempt at fixing HBASE-20173 [AMv2] DisableTableProcedure concurrent to ServerCrashProcedure can deadlock
The scenario is a SCP after processing WALs, goes to assign regions that
were on the crashed server but a concurrent Procedure gets in there
first and tries to unassign a region that was on the crashed server
(could be part of a move procedure or a disable table, etc.). The
unassign happens to run AFTER SCP has released all RPCs that
were going against the crashed server. The unassign fails because the
server is crashed. The unassign used to suspend itself only it would
never be woken up because the server it was going against had already
been processed. Worse, the SCP could not make progress because the
unassign was suspended with the lock on a region that it wanted to
assign held making it so it could make no progress.
In here, we add to the unassign recognition of the state where it is
running post SCP cleanup of RPCs. If present, unassign moves to finish
instead of suspending itself.
Includes a nice unit test made by Duo Zhang that reproduces nicely the
hung scenario.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/FailedRemoteDispatchException.java
Moved this class back to hbase-procedure where it belongs.
M hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/NoNodeDispatchException.java
M hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/NoServerDispatchException.java
M hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/NullTargetServerDispatchException.java
Specializiations on FRDE so we can be more particular when we say there
was a problem.
M hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/RemoteProcedureDispatcher.java
Change addOperationToNode so we throw exceptions that give more detail
on issue rather than a mysterious true/false
M hbase-protocol-shaded/src/main/protobuf/MasterProcedure.proto
Undo SERVER_CRASH_HANDLE_RIT2. Bad idea (from HBASE-20173)
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
Have expireServer return true if it actually queued an expiration. Used
later in this patch.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
Hide methods that shouldn't be public. Add a particular check used out
in unassign procedure failure processing.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MoveRegionProcedure.java
Check that server we're to move from is actually online (might
catch a few silly move requests early).
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStates.java
Add doc on ServerState. Wasn't being used really. Now we actually stamp
a Server OFFLINE after its WAL has been split. Means its safe to assign
since all WALs have been processed. Add methods to update SPLITTING
and to set it to OFFLINE after splitting done.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionTransitionProcedure.java
Change logging to be new-style and less repetitive of info.
Cater to new way in which .addOperationToNode returns info (exceptions
rather than true/false).
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
Add looking for the case where we failed assign AND we should not
suspend because we will never be woken up because SCP is beyond
doing this for all stuck RPCs.
Some cleanup of the failure processing grouping where we can proceed.
TODOs have been handled in this refactor including the TODO that
wonders if it possible that there are concurrent fails coming in
(Yes).
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/ServerCrashProcedure.java
Doc and removing the old HBASE-20173 'fix'.
Also updating ServerStateNode post WAL splitting so it gets marked
OFFLINE.
A hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestServerCrashProcedureStuck.java
Nice test by Duo Zhang.
Signed-off-by: Umesh Agashe <uagashe@cloudera.com>
Signed-off-by: Duo Zhang <palomino219@gmail.com>
Signed-off-by: Mike Drob <mdrob@apache.org>
Adds new stripped-down, faster ByteBufferKeyValue comparator
(BBKV is the base Cell-type in hbase2). Creates an instance
of new Comparator each time we create new memstore rather
than use the universal CellComparator.
Remove unused and unneeded Interfaces from Cell base type.
- CacheStats won't generate NaN metrics.
- JSONBean class will serialize special floating point values as
"NaN", "Infinity" or "-Infinity"
Signed-off-by: Andrew Purtell <apurtell@apache.org>
Add method the CellComparator Interface. Add implementation to
meta comparator so we don't fall back to the default comparator.
Includes a nothing change to hbase-server/pom.xml just to provoke
build.
When we pread, we don't force the read to read all of the next block header.
However, when we get into a race condition where two opener threads try to
cache the same block and one thread read all of the next block header and
the other one didn't, it will fail the open process. This is especially important
in a splitting case where it will potentially fail the split process.
Instead, in the caches, we should only fail if the required blocks are different.
Signed-off-by: Andrew Purtell <apurtell@apache.org>
Change the MemStore size accounting so we don't synchronize across three
volatiles applying deltas. Instead:
+ Make MemStoreSize, a datastructure of our memstore size longs, immutable.
+ Undo MemStoreSizing being an instance of MemStoreSize; instead it has-a.
+ Make two MemStoreSizing implementations; one thread-safe, the other not.
+ Let all memory sizing longs run independent, untied by
synchronize (Huaxiang and Anoop suggestion) using atomiclongs.
+ Review all use of MemStoreSizing. Many are single-threaded and do
not need to be synchronized; use the non-thread safe counter.
TODO: Use this technique accounting at the global level too.
Add backoff when stuck in RegionTransitionProcedure, the subclass of
AssignProcedure and UnassignProcedure. Can happen when we go to
transition but the current Region state is not what we expect.
M hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/Procedure.java
Add doc on being able to suspend and wait on a timeout.
M hbase-protocol-shaded/src/main/protobuf/MasterProcedure.proto
Add 'attempt' counter so we can do backoff when we get stuck.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
Add persistence of new 'attempt' counter
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionTransitionProcedure.java
Doc data members that are persisted by subclasses given this is 'odd'.
Add a counter for 'attempts' used when 'stuck' to implement backoff.
Add suspend with timeout when 'stuck'. Add callback when timeout is
exhausted which does wakeup of this procedure.
A hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestUnexpectedStateException.java
Test of backoff.
Fix test that depended upon flush being slow and one family only.
Fix MemStoreSize compare to allow passing alternate implementation
(needed when IMC was no longer default everywhere).
HBase server versioned is checked after connecting to the server and then following operations are not allowed:
-fix, -fixAssignments, -fixMeta, -fixHdfsHoles, -fixHdfsOrphans, -fixTableOrphans, -fixHdfsOverlaps, -maxMerge
-sidelineBigOverlaps, -maxOverlapsToSideline, -fixSplitParents, -removeParents, -fixEmptyMetaCells
-repair, -repairHoles
* Make CleanerChore less chatty: move WARN message to DEBUG when we expect non-empty dirs
* Make CleanerChore less chatty: move IOE we'll retry to INFO
* CleanerChore should treat IOE for FileStatus as a failure
* Add tests asserting assumptions in above
Signed-off-by: Reid Chan <reidddchan@outlook.com>
Signed-off-by: Mike Drob <mdrob@apache.org>
in-memory-compaction logging
Adds logging of CompactingMemStore configuration on construction.
Add logging of detail about Store on creation including memstore type.
Add chapter to refguide on new in-memory compaction feature.
When prefetch on open is specified, there is a deadlocking case
where if the prefetch is cancelled, the PrefetchExecutor interrupts
the threads if necessary, when that happens in FileIOEngine, it
causes an ClosedByInterruptException which is a subclass of
ClosedChannelException. If we retry all ClosedChannelExceptions,
this will lock as this access is expected to be interrupted.
This change removes calling refreshFileConnections for
ClosedByInterruptExceptions.
Signed-off-by: Andrew Purtell <apurtell@apache.org>
The Master asks a RegionServer whether a Region can be split or not, primarily to
verify that the region is not closing, opening, etc. This change has the RegionServer
also consult the configured RegionSplitPolicy.
Signed-off-by: Josh Elser <elserj@apache.org>
Remove commons-cli and commons-collections4 use. Account
for the newer internal protobuf version of 3.5.1.
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Mike Drob <mdrob@apache.org>
Changes for HBASE-20027 seem to cause UI not showing up on default port in standalone mode. For concurrent
unit test execution, individual tests can set hbase.localcluster.assign.random.ports to true or modify
test/resources/hbase-site.xml.
Changes for HBASE-20027 seem to cause UI not showing up on default port in standalone mode. For concurrent
unit test execution, individual tests can set hbase.localcluster.assign.random.ports to true or modify
test/resources/hbase-site.xml.
Adds a prepare step to RecoverMetaProcedure in which we test for
cluster up and master being up. If not up, we fail the run.
Modified hbase-server/src/main/java/org/apache/hadoop/hbase/master/cleaner/HFileCleaner.java
Modified hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ChunkCreator.java
Minor log cleanup.
Modified hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/RecoverMetaProcedure.java
Add pepare step.
Modified hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestAssignmentManagerMetrics.java
Debug for the failing test....
Added hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestRecoverMetaProcedure.java
Test the prepare step goes down if master or cluster are down.
in-memory compactions)
Log less. Log using same format as used elsewhere in log.
Align logs in HFileArchiver with how we format elsewhere. Removed
redundant 'region' qualifiers, tried to tighten up the emissions so
easier to read the long lines.
M hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ChunkCreator.java
Add a label for each of the chunkcreators we make (I was confused by
two chunk creater stats emissions in log file -- didn't know that one
was for data and the other index).
M hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/CompactSplit.java
Formatting. Log less.
M hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStoreCompactionStrategy.java
Make the emissions in here trace-level. When more than a few regions,
log is filled with this stuff.
HBASE-19435 implements a fix for reopening file channels when they are unnexpected closed
to avoid disabling the BucketCache. However, it was missed that the the channels might not
actually be completely closed (the write or read channel might still be open
(see https://docs.oracle.com/javase/7/docs/api/java/nio/channels/ClosedChannelException.html)
This commit closes any open channels before creating a new channel.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/DoNotRetryRegionException.java
M hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/MergeRegionException.java
Allow passing cause to Constructor.
M hbase-protocol-shaded/src/main/protobuf/MasterProcedure.proto
Add prepare step to move procedure.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
Add check that regions to merge are actually online to the Constructor
so we can fail fast if they are offline
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MoveRegionProcedure.java
Add prepare step. Check regions and context and skip move if not right.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/SplitTableRegionProcedure.java
Add check parent region is online to constructor.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/AbstractStateMachineTableProcedure.java
Add generic check region is online utility function for use by subclasses.
M hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionMove.java
Add test that we fail if we try to move an offlined region.
Add Fail-Fast to Procedures by throwing exception out of Procedure
constructor so if move but table is disabled or if master is going
down, etc., we can give notice before the procedure is scheduled.
Will help guard against scheduling Procedures that will have a hard
time succeeding; e.g. a move when table is offline.
Also fixed bug around table state where we presumed ENABLED though no
entry in hbase:meta (we were using this mechanism for whether a table
existed or not).
M hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionMove.java
Test stolen from HBASE-20131
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableState.java
Add convenience isEnabled/isDisabled
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
Promote assert state to throw exception.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterServices.java
Add isClusterUp
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
Move constructor now throws exception
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MoveRegionProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/SplitTableRegionProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/DisableTableProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/ModifyTableProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/RestoreSnapshotProcedure.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/TruncateTableProcedure.java
Do environment check at construction and fail-fast if hostile.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/AbstractStateMachineTableProcedure.java
Add preflightCheck utility method.
M hbase-client/src/main/java/org/apache/hadoop/hbase/MetaTableAccessor.java
Removed setting time setting table state; broke when using other than
default environment edge masked by presumption that no state meant
active.
Allow that DisableTableProcedue can grab a region lock before
ServerCrashProcedure can. Cater to this cricumstance where SCP
was not unable to make progress by running the search for RIT
against the crashed server a second time, post creation of all
crashed-server assignemnts. The second run will uncover such as
the above DisableTableProcedure unassign and will interrupt its
suspend allowing both procedures to make progress.
M hbase-protocol-shaded/src/main/protobuf/MasterProcedure.proto
Add new procedure step post-assigns that reruns the RIT finder method.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
Make this important log more specific as to what is going on.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
Better explanation as to what is going on.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/ServerCrashProcedure.java
Add extra step and run handleRIT a second time after we've queued up
all SCP assigns. Also fix a but. SCP was adding an assign of a RIT
that was actually trying to unassign (made the deadlock more likely).
We assumed that we can run for loop from 0 to lastStep sequentially. MergeTableRegionProcedure skips step 2. So, when i is 0 the procedure is already at step 3.
Added a method StateMachineProcedure#getCurrentStateId that can be used from test code only.
On failed RPC we expire the server and suspend expecting the
resultant ServerCrashProcedure to wake us back up again. In tests,
TestRSGroup hung because it failed to schedule a server expiration
because the server was already expired undergoing processing (the
test was shutting down). Deal with this case by having expire
servers return false if unable to expire. Callers will then know
where a ServerCrashProcedure has been scheduled or not.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
Have expireServer return true if successful.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionTransitionProcedure.java
The log that included an exception whose message was the current
procedure as a String totally baffled me. Make it more obvious what
exception is.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/UnassignProcedure.java
If failed expire of a server, wake our procedure -- do not suspend --
and presume ok to move region to CLOSED state (because going down or
concurrent crashed server processing ongoing).
* rely on git plumbing commands when checking if we've built the site for a particular commit already
* switch to forcing '-e' for bash
* add command line switches for: path to hbase, working directory, and publishing
* only export JAVA/MAVEN HOME if they aren't already set.
* add some docs about assumptions
* Update javadoc plugin to consistently be version 3.0.0
* avoid duplicative site invocations on reactor modules
* update use of cp command so it works both on linux and mac
* manually skip enforcer plugin during build
* still doing install of all jars due to MJAVADOC-490, but then skip rebuilding during aggregate reports.
* avoid the pager on git-diff by teeing to a log file, which also helps later reviewing in the case of big changesets.
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Misty Stanley-Jones <misty@apache.org>
Conflicts:
hbase-backup/pom.xml
hbase-spark-it/pom.xml
Revert of the revert, i.e. reapply. Thought this had broken the build
but it was a bad nightly. Putting it back.
Revert "Revert "HBASE-20069 fix existing findbugs errors in hbase-server; ADDENDUM Address review""
This reverts commit 07eae00ec1.
Reapplication of a patch temporarily removed...
I thought this was causing issue but now I don't think it the culprit.
Revert "Revert "HBASE-20092 Fix TestRegionMetrics#testRegionMetrics""
This reverts commit 367d316781.
Allow OPEN as a possible state when update region transition state.
Usually state is OPENING but if crash before finish step is completed,
on replay, master may have read that the state is OPEN from meta table
and so will think it open... When we replay the procedure finish, allow
that the region is already OPEN.
Fix MoveRandomRegionOfTableAction. It depended on old AM behavior.
Make it do explicit move as is required in AMv3; w/o it, it was just
closing region causing test to fail.
Fix pom so hadoop3 profile specifies a different netty3 version.
Bunch of logging format change that came of trying trying to read
the spew from this test.
This reverts commit bc080e7500.
Conflicts:
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/Segment.java
patch reverted changes that happened in parallel without explanation. see jira.
- Added ADMIN permission check for following rpc calls:
normalize, setNormalizerRunning, runCatalogScan, enableCatalogJanitor, runCleanerChore,
setCleanerChoreRunning, execMasterService, execProcedure, execProcedureWithRet
- Moved authorizationEnabled check to start of AccessChecker's functions. Currently, and IDK why,
we call authManager.authorize() first and then discard its result if authorizationEnabled is false. Weird.
Negative Remaining KVs and progress percent greater than 100 is because CompactionProgress#totalCompactingKVs is sometimes less than CompactionProgress#currentCompactedKVs.
Changes add a getter to CompactionProgress#totalCompactingKVs and from inside getter warning is logged. currentCompactedKVs are return when totalCompactingKVs are less than current.
Signed-off-by: Michael Stack <stack@apache.org>
Revert "Revert "HBASE-2004 TestClientClusterStatus is flakey""
This is a revert of a revert, i.e. a reapplication, just so I can fix
the JIRA number.
This reverts commit 6796b8e21f.
LocalHBaseCluster forces random port assignment for sake of concurrent unit test
execution friendliness, but we still need a positive test for RPC and info port
assignment.
The 1.x functionality of Master DDL operations is that "post" observer hooks
are only invoked when the DDL action was successful. With the async-ness of
ProcV2, we find ourselves in a case where the post-hook may be invoked before
the Procedure runs and fails. We need to introduce some blocking to wait and
see if the Procedure is going to fail on a precondition before invoking the hook.
Signed-off-by: Michael Stack <stack@apache.org>
Remove assert in splittableregionprocedure. It was in the prepare.
Was causing fail in legit case where a region split follows a
table split BEFORE the parent has been GC'd. The region split
finds the parent in SPLIT state which is right. The assert was
having us fail. No need.
Also disabled TestHTrace since not supported in 2.0.0 and flakey.
Only call server.checkIfShouldMoveSystemRegionAsync if a node has been
added. Do not call it if only one regionserver in cluster. Make it
so ServerCrashProcedure runs before it. Add logging if
server.checkIfShouldMoveSystemRegionAsync was responsible for
MOVE (Previous was a mystery when it cut in).
Previous we'd call it when there was a nodeChildrenChanged. These
happen before nodeDeleted. If a server crashed,
checkIfShouldMoveSystemRegionAsync could run first, find the
server that had not yet registered as crashed, find system
tables on it and then try to move them. It would fail because
server would not respond to RPC. The region move would then
be waiting on the servercrashprocedure to wake it up when
done processing but this move had locked the region so
SCP couldn't run....
Serializing, if appropriate, write the hbase-1.x version of the
Comparator to the hfile trailer so hbase-1.x files can read hbase-2.x
hfiles (they are the same format).
This patch adds mirroring of table state out to zookeeper. HBase-1.x
clients look for table state in zookeeper, not in hbase:meta where
hbase-2.x maintains table state.
The patch also moves and refactors the 'migration' code that was put in
place by HBASE-13032.
D hbase-client/src/main/java/org/apache/hadoop/hbase/CoordinatedStateException.java
Unused.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
Move table state migration code from Master startup out to
TableStateManager where it belongs. Also start
MirroringTableStateManager dependent on config.
A hbase-server/src/main/java/org/apache/hadoop/hbase/master/MirroringTableStateManager.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/TableStateManager.java
Move migration from zookeeper of table state in here. Also plumb in
mechanism so subclass can get a chance to look at table state as we do
the startup fixup full-table scan of meta.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
Bug-fix. Now we create regions in CLOSED state but we fail to check
table state; were presuming table always enabled. Meant on startup
there'd be an unassigned region that never got assigned.
A hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMirroringTableStateManager.java
Test migration and mirroring.
Value of 'htd' is null as it is initialized in the constructor but when the object is deserialized its null. Got rid of member variable htd and made it local to method.
Josh Elser
zhangduo
Michael Stack
Sean Busbey
Mike Drob
taiynlee
tedyu
Xu Cang
jingyuntian
Guanghao Zhang
Balazs Meszaros
Nihal Jain
eric-maynard
Peter Somogyi
Andrew Purtell
maoling
eshcar
huzheng
Toshihiro Suzuki
meiyi
Thiruvel Thirumoolan
Apekshit Sharma
Zach York
Guanghao Zhang
Chia-Ping Tsai
Umesh Agashe
Sakthi
Rich Fecher
Huaxiang Sun
Wei-Chiu Chuang
lujie
Guangxu Cheng
Ashish Singhi
BELUGA BEHR
Jan Hentschel
Vasudevan
Yu Li
Rajeshbabu Chintaguntla
Reid Chan
anoopsamjohn
Peter Somogyi
Chance Li
Mike Grimes
Sahil Aggarwal
haxiaolin
Sergey Soldatov
gsheffi
Esteban Gutierrez
anastas
Ben Lau
Pankaj Kumar
Aman Poonia