Network identities should be bound late. Remote addresses should be
resolved at the last possible moment, just before connect(). Network
identity mappings can change, so our code should not inappropriately
cache them. Otherwise we might miss a change and fail to operate normally.
Revert "HBASE-14544 Allow HConnectionImpl to not refresh the dns on errors"
Removes hbase.resolve.hostnames.on.failure and related code. We always
resolve hostnames, as late as possible.
Preserve InetSocketAddress caching per RPC connection. Avoids potential
lookups per Call.
Replace InetSocketAddress with Address where used as a map key. If we want
to key by hostname and/or resolved address we should be explicit about it.
Using Address chooses mapping by hostname and port only.
Add metrics for potential nameservice resolution attempts, whenever an
InetSocketAddress is instantiated for connect; and metrics for failed
resolution, whenever InetSocketAddress#isUnresolved on the new instance
is true.
* Use ServerName directly to build a stub key
* Resolve and cache ISA on a RpcChannel as late as possible, at first call
* Remove now invalid unit test TestCIBadHostname
We resolve DNS at the latest possible time, at first call, and do not
resolve hostnames for creating stubs at all, so this unit test cannot
work now.
Reviewed-by: Mingliang Liu <liuml07@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
This PR is a follow-up of HBASE-25181 (#2539), where several issues were
discussed on the PR:
1. Currently we use PBKDF2WithHmacSHA1 key generation algorithm to generate a
secret key for HFile / WalFile encryption, when the user is defining a string
encryption key in the hbase shell. This algorithm is not secure enough and
not allowed in certain environments (e.g. on FIPS compliant clusters). We are
changing it to PBKDF2WithHmacSHA384. It will not break backward-compatibility,
as even the tables created by the shell using the new algorithm will be able
to load (e.g. during bulkload / replication) the HFiles serialized with the
key generated by an old algorithm, as the HFiles themselves already contain
the key necessary for their decryption.
Smaller issues fixed by this commit:
2. Improve the documentation e.g. with the changes introduced by HBASE-25181
and also by some points discussed on the Jira ticket of HBASE-25263.
3. In EncryptionUtil.createEncryptionContext the various encryption config
checks should throw IllegalStateExceptions instead of RuntimeExceptions.
4. Test cases in TestEncryptionTest.java should be broken down into smaller
tests.
5. TestEncryptionDisabled.java should use ExpectedException JUnit rule to
validate exceptions.
closes#2676
Signed-off-by: Peter Somogyi <psomogyi@apache.org>
* HBASE-25050 - We initialize Filesystems more than once.
* Ensuring that calling the FS#get() will only ensure FS init.
* Fix for testfailures. We should pass the entire path and no the scheme
alone
* Cases where we don't have a scheme for the URI
* Address review comments
* Add some comments on why FS#get(URI, conf) is getting used
* Adding the comment as per Sean's review
Signed-off-by: Sean Busbey <busbey@apache.org>
Signed-off-by: Michael Stack <stack@apache.org>
* HBASE-25187 Improve SizeCachedKV variants initialization
* HBASE-25187 Improve SizeCachedKV variants initialization
* The BBKeyValue also can be optimized
* Change for SizeCachedKeyValue
* Addressing revew comments
* Fixing checkstyle and spot bugs comments
* Spot bug fix for hashCode
* Minor updates make the rowLen as short and some consturctor formatting
* Change two more places where there was a cast
Prior to this patch hbase always used the MD5 hash algorithm to store a hash for encryption keys.
This hash is needed to verify the secret key of the subject. (e.g. making
sure that the same secrey key is used during encrypted HFile read and write).
The MD5 algorithm is considered weak, and can not be used in some
(e.g. FIPS compliant) clusters.
In this patch we:
- add a config parameter to globally enable/disable column family encryption (def enabled)
- introduce a backward compatible way of specifying the hash algorithm.
This enable us to use newer and more secure hash algorithms like SHA-384
or SHA-512 (which are FIPS compliant).
- add a config parameter to fail if an hfile is encountered that uses a
different hash algorithm than the one currently configured to ease validation after
migrating key hash algorithms (def disabled)
Closes#2539
Signed-off-by: Sean Busbey <busbey@apache.org>
Signed-off-by: Esteban Gutierrez <esteban@apache.org>
Wire up the `ConfigurationObserver` chain for
`RegionNormalizerManager`. The following configuration keys support
hot-reloading:
* hbase.normalizer.throughput.max_bytes_per_sec
* hbase.normalizer.split.enabled
* hbase.normalizer.merge.enabled
* hbase.normalizer.min.region.count
* hbase.normalizer.merge.min_region_age.days
* hbase.normalizer.merge.min_region_size.mb
Note that support for `hbase.normalizer.period` is not provided
here. Support would need to be implemented generally for the `Chore`
subsystem.
Signed-off-by: Bharath Vissapragada <bharathv@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: Aman Poonia <aman.poonia.29@gmail.com>
The core change here is to the loop in
`SimpleRegionNormalizer#computeMergeNormalizationPlans`. It's a nested
loop that walks the table's region chain once, looking for contiguous
sequences of regions that meet the criteria for merge. The outer loop
tracks the starting point of the next sequence, the inner loop looks
for the end of that sequence. A single sequence becomes an instance of
`MergeNormalizationPlan`.
Signed-off-by: Huaxiang Sun <huaxiangsun@apache.org>
Add the documentation when
HConstants#REPLICATION_DROP_ON_DELETED_TABLE_KEY was deprecated and when
it is expected to be removed.
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Make it so WALPlayer can replay recovered.edits files.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/WALInputFormat.java
Allow for WAL files that do NOT have a startime in their name.
Use the 'generic' WAL-filename parser instead of the one that
used be local here. Implement support for 'startTime' filter.
Previous was just not implemented.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/WALPlayer.java
Checkstyle.
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/AbstractFSWALProvider.java
Use the new general WAL name timestamp parser.
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WAL.java
Utility for parsing timestamp from WAL filename.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRecoveredEdits.java
Export attributes about the local recovered.edits test file
so other tests can play with it.
Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>
* Admin API getLogEntries() for ring buffer use-cases: so far, provides balancerDecision and slowLogResponse
* Refactor RPC call for similar use-cases
* Single RPC API getLogEntries() for both Master.proto and Admin.proto
Closes#2261
Signed-off-by: Andrew Purtell <apurtell@apache.org>
* Break subclass referencing of MetaCellComparator from superclass CellComparatorImpl
static initializer by moving META_COMPARATOR to subclass MetaCellComparator
Closes#2329
Signed-off-by: Duo Zhang <zhangduo@apache.org>
when neighbor is larger than average size
* add `testMergeEmptyRegions` to explicitly cover different
interleaving of 0-sized regions.
* fix bug where merging a 0-size region is skipped due to large
neighbor.
* remove unused `splitPoint` from `SplitNormalizationPlan`.
* generate `toString`, `hashCode`, and `equals` methods from Apache
Commons Lang3 template on `SplitNormalizationPlan` and
`MergeNormalizationPlan`.
* simplify test to use equality matching over `*NormalizationPlan`
instances as plain pojos.
* test make use of this handy `TableNameTestRule`.
* fix line-length issues in `TestSimpleRegionNormalizer`
Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: huaxiangsun <huaxiangsun@apache.org>
Signed-off-by: Aman Poonia <aman.poonia.29@gmail.com>
* refactor how we use connection and async connection to rely on their access methods
* refactor initialization and cleanup of the shared connection
* incompatibly change HCTU's Configuration member variable to be final so it can be safely accessed from multiple threads.
Closes#2180
Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Also fix three bugs:
* We were trying to delete non-empty directory; weren't doing
accounting for meta WALs where meta had moved off the server
(successfully)
* We were deleting split WALs rather than archiving them.
* We were not handling corrupt files.
Deprecations and removal of tests of old system.
Signed-off-by: Anoop Sam John <anoopsamjohn@apache.org>
Writing a test for this is tricky. There is enough coverage for
functional tests. Only concern is performance, but there is enough
logging for it to detect timed out/badly performing sync calls.
Additionally, this patch decouples the ZK event processing into it's
own thread rather than doing it in the EventThread's context. That
avoids deadlocks and stalls of the event thread.
Signed-off-by: Andrew Purtell <apurtell@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Simplify our Normalizer story to have just a single, configurable
implementation.
* fold the features of `MergeNormalizer` into
`SimpleRegionNormalizer`, removing the intermediate abstract class.
* configuration keys for merge-only features now share a common
structure.
* add configuration to selectively disable normalizer split/merge
operations.
* `RegionNormalizer` now extends `Configurable` instead of creating a
new instance of `HBaseConfiguration` or snooping one off of other
fields.
* avoid the extra RPCs by using `MasterServices` instead of
`MasterRpcServices`.
* boost test coverage of all the various flags and feature
combinations.
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: huaxiangsun <huaxiangsun@apache.org>
This utility is useful for any module that wants to detect
dynamic config changes. Having it to hbase-common makes it
accessible to all the other modules.
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
This is needed for the hbase-native-client to compile. Also ships
the includes in the assembly tar.
Signed-off-by: Marc <phrocker@apache.org>
Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Signed-off-by: Anoop Sam John <anoopsamjohn@apache.org>
Signed-off-by: ramkrish86 <ramkrishna@apache.org>
Simplify the new user experience shipping a configuration that enables
a fresh checkout or tarball distribution to run in standalone mode
without direct user configuration. This change restores the behavior
we had when running on Hadoop 2.8 and earlier.
Patch for master includes an update to the book. This change will be
omitted when backporting to earlier branches.
Signed-off-by: stack <stack@apache.org>
Signed-off-by: Josh Elser <elserj@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Move the random free port generate back into hbasecommontestingutility
from hbasetestingutility.
Add a create simple kdc server utility that will start a kdc server and
if a bindexception, create a new one on a new random port in hbase-common.
Add new BoundSocketMaker helpful when trying to manufacture
BindExceptions because of port clash.
Change thrift and http kdc tests to use this new utility (removes
code duplication around kdc server setup).
* Reorganize MOB compaction tests for more reuse.
* Add tests for mob compaction after snapshot clone operations
* note the original table used to write a given mob hfile and use that to find it later.
Signed-off-by: Esteban Gutierrez <esteban@apache.org>
Master rpc server end point doesn't bind to localhost's
IP address by default. Instead, it looks up the hostname and
binds to the endpoint to which it resolves. MasterRegistry should
do the same when building the default server end point to talk to.
Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>
There were a couple of issues.
- There was a leak of a file descriptor for hbck lock file. This
was contributing to all the "ConnectionRefused" stack traces since
it was trying to renew lease for an already expired mini dfs cluster.
This issue was there for a while, just that we noticed it now.
- After upgrade to JUnit 4.13, it looks like the behavior for test
timeouts has changed. Earlier the timeout seems to have applied for
each parameterized run, but now it looks like it is applied across
all the runs.
This patch fixes both the issues.
Signed-off-by: Stack <stack@apache.org>
Signed-off-by: Jan Hentschel <jan.hentschel@ultratendency.com>
Implements a master based registry for clients.
- Supports hedged RPCs (fan out configured via configs).
- Parameterized existing client tests to run with multiple registry combinations.
- Added unit-test coverage for the new registry implementation.
Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>
Signed-off-by: stack <stack@apache.org>
Signed-off-by: Andrew Purtell <apurtell@apache.org>
- MOB compaction is now handled in-line with per-region compaction on region
servers
- regions with mob data store per-hfile metadata about which mob hfiles are
referenced
- admin requested major compaction will also rewrite MOB files; periodic RS
initiated major compaction will not
- periodically a chore in the master will initiate a major compaction that
will rewrite MOB values to ensure it happens. controlled by
'hbase.mob.compaction.chore.period'. default is weekly
- control how many RS the chore requests major compaction on in parallel
with 'hbase.mob.major.compaction.region.batch.size'. default is as
parallel as possible.
- periodic chore in master will scan backing hfiles from regions to get the
set of referenced mob hfiles and archive those that are no longer
referenced. control period with 'hbase.master.mob.cleaner.period'
- Optionally, RS that are compacting mob files can limit write
amplification by not rewriting values from mob hfiles over a certain size
limit. opt-in by setting 'hbase.mob.compaction.type' to 'optimized'.
control threshold by 'hbase.mob.compactions.max.file.size'.
default is 1GiB
- Should smoothly integrate with existing MOB users via rolling upgrade.
will delay old MOB file cleanup until per-region compaction has managed
to compact each region at least once so that used mob hfile metadata can
be gathered.
This is causing me issues with parallel test runs.
Also allow setting the surefire reports and temp directories via command line.
Signed-off-by: stack <stack@apache.org>
These classifications come of running at various fork counts.. A test
may complete quick if low fork count but if it is accessing disk, it
will run much slower if fork count is high. This edit accommodates
some of this phenomenon.
Signed-off-by: Bharath Vissapragada <bharathv@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: Jan Hentschel <janh@apache.org>
Codecs don't have access to what CellComparator to use. Backfill.
M hbase-common/src/main/java/org/apache/hadoop/hbase/CellComparator.java
Adds a new compareRows with default implementation that takes a ByteBuffer.
Needed by the index in a block encoder implementation.
M hbase-common/src/main/java/org/apache/hadoop/hbase/CellComparatorImpl.java
Adds implementation for meta of new compareRows method. Adds utility
method for figuring comparator based off tablename.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/AbstractDataBlockEncoder.java
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/RowIndexCodecV1.java
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/RowIndexSeekerV1.java
Comparator is in context. Remove redundant handling.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/DataBlockEncoder.java
Comparator is in context. Remove redundant handling. Clean javadoc.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/HFileBlockDecodingContext.java
Clean javadoc.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/RowIndexEncoderV1.java
Cache context so can use it to get comparator to use later.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileContext.java
Cache cellcomparator to use. Javdoc on diff between HFileContext and
HFileInfo.
M hbase-common/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileContextBuilder.java
Add CellComparator
M hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/HFileOutputFormat2.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFile.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderImpl.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileWriterImpl.java
M hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileWriter.java
Remove comparator caching. Get from context instead.
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/FixedFileTrailer.java
Skip a reflection if we can.
M hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileInfo.java
Javadoc. Removed unused filed.
Signed-off-by: Anoop Sam John <anoopsamjohn@apacher.org>
Signed-off-by: Ramkrishna <ramkrishna.s.vasudevan@intel.com>
Signed-off-by: Jan Hentschel <janh@apache.org>
Make hbase:meta region schema dynamic.
Patch has been under development a good while and its focus has changed
a few times so its bloated with fixup from older versions.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/TableStateManager.java
M hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
Shut down access to internals and removed unused methods.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/EnableTableProcedure.java
Cleanup/refactor section on replica-handling.
M hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java
Get hbase:meta schema from filesystem rather than from hard-coding.
We have a compile-time guarantee to either have a category array
of length zero or one because the category annotation is non-repeatable.
Also tries to clean up the checking for unit-test annotations.
Closes#1057
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: Bharath Vissapragada <bharathv@apache.org>
Decouple the HBase internals such that someone can implement
their own SASL-based authentication mechanism and plug it into
HBase RegionServers/Masters.
Comes with a design doc in dev-support/design-docs and an example in
hbase-examples known as "Shade" which uses a flat-password file
for authenticating users.
Closes#884
Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org>
Signed-off-by: Andrew Purtell <apurtell@apache.org>
Signed-off-by: Reid Chan <reidchan@apache.org>
Make it so hbase:meta can be altered. TableState for hbase:meta
was hardcoded ENABLED. Make it dynamic. State is now kept in
current active Master. It is transient so falls back to default
if Master crashes. Add to registry a getMetaTableState
which reads mirrored state from zookeeper (NOT from Master and
defaults ENABLED if no implementation or error fetching state).
hbase:meta schema will be bootstrapped from the filesystem.
Changes to filesystem schema are atomic so we should be ok if
Master fails mid-edit (TBD). Undoes a bunch of guards that
prevented our being able to edit hbase:meta.
TODO: Tests, more clarity around hbase:meta table state, and undoing
references to hard-coded hbase:meta regioninfo.
M hbase-client/src/main/java/org/apache/hadoop/hbase/MetaTableAccessor.java
Throw illegal access exception if you try to use MetaTableAccessor
getting state of the hbase:meta table.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
Add fetching of hbase:meta table state from registry. Adds cache of
tablestates w/ a ttl of 1 second (adjustable).
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
Add querying registry for hbase:meta table state.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ZKAsyncRegistry.java
Add querying of mirrored table state for hbase:meta table.
M hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
Shutdown access.
M hbase-server/src/main/java/org/apache/hadoop/hbase/TableDescriptors.java
Just cleanup.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/TableStateManager.java
Add state holder for hbase:meta. Removed unused methods.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
Shut down access.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/DisableTableProcedure.java
Allow hbase:meta to be disabled.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/EnableTableProcedure.java
Allow hbase:meta to be enabled.
Signed-off-by: Bharath Vissapragada <bharathv@apache.org>
All the clients need to know the master RPC end points while using master
based registry for creating cluster connections. This patch amends the
test cluster utility to populate these configs in the base configuration
object used to spin up the cluster.
The config key added here ("hbase.master.addrs") is used in the subsequent
patches for HBASE-18095.
Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>
Removes the closeRegion flag added by HBASE-23181 and instead
relies on reading meta WALEdit content. Modified how qualifier is
written when the meta WALEdit is for a RegionEventDescriptor
so the 'type' is added to the qualifer so can figure type
w/o having to deserialize protobuf value content: e.g.
HBASE::REGION_EVENT::REGION_CLOSE
Added doc on WALEdit and tried to formalize the 'meta' WALEdit
type and how it works. Needs complete redo in part as suggested
by HBASE-8457. Meantime, some doc and cleanup.
Also changed the LogRoller constructor to remove redundant param.
Because of constructor change, need to change also
TestFailedAppendAndSync, TestWALLockup, TestAsyncFSWAL &
WALPerformanceEvaluation.java
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Signed-off-by: Lijin Bin <binlijin@apache.org>
Make it so hbase:meta can be altered. TableState for hbase:meta
is kept in Master. State is in-memory transient so if Master
fails, hbase:meta is ENABLED again. hbase:meta schema will be
bootstrapped from the filesystem. Changes to filesystem schema
are atomic so we should be ok if Master fails mid-edit (TBD)
Undoes a bunch of guards that prevented our being able to edit
hbase:meta. At minimmum, need to add in a bunch of WARNING.
TODO: Tests, more clarity around hbase:meta table state, and undoing
references to hard-coded hbase:meta regioninfo.
M hbase-client/src/main/java/org/apache/hadoop/hbase/MetaTableAccessor.java
Throw illegal access exception if you try to use MetaTableAccessor
getting state of the hbase:meta table.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
For table state, go to master rather than go to meta direct. Going
to meta won't work for hbase;meta state. Puts load on Master.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
Change isTableDisabled/Enabled implementation to ask the Master instead.
This will give the Master's TableStateManager's opinion rather than
client figuring it for themselves reading meta table direct.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
TODO: Cleanup in here. Go to master for state, not to meta.
M hbase-client/src/main/java/org/apache/hadoop/hbase/client/ZKAsyncRegistry.java
Logging cleanup.
M hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
Shutdown access.
M hbase-server/src/main/java/org/apache/hadoop/hbase/TableDescriptors.java
Just cleanup.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/TableStateManager.java
Add state holder for hbase:meta.
Removed unused methods.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
Shut down access.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/DisableTableProcedure.java
Allow hbase:meta to be disabled.
M hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/EnableTableProcedure.java
Allow hbase:meta to be enabled.
Signed-off-by: Ramkrishna <ramkrishna.s.vasudevan@intel.com>
Michael Stack
Duo Zhang
Adam
shahrs87
Andrew Purtell
Mate Szalay-Beko
ramkrish86
gvprathyusha6
WenFeiYi
Nick Dimiduk
sanjeetnishad95
Jan Hentschel
niuyulin
Guanghao Zhang
Viraj Jasani
XinSun
bsglz
Sean Busbey
Peter Somogyi
Bo Cui
pengmq1
Bharath Vissapragada
Anoop Sam John
Mingliang Liu
Sambit Mohapatra
Yu Wang
Mark Robert Miller
Reid Chan
Abhinaba Sarkar
Vladimir Rodionov
stack
Jan Hentschel
Josh Elser
Aman Poonia
belugabehr
Viraj Jasani
chenxu14
Reid Chan
Geoffrey Jacoby
haxiaolin
Istvan Toth