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Hive QA commented on HIVE-21210: -------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || || || || || {color:brown} Prechecks {color} || | {color:green}+1{color} | {color:green} @author {color} | {color:green} 0m 0s{color} | {color:green} The patch does not contain any @author tags. {color} | || || || || {color:brown} master Compile Tests {color} || | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 1m 17s{color} | {color:blue} Maven dependency ordering for branch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 6m 13s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 14s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 44s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m 30s{color} | {color:blue} common in master has 65 extant Findbugs warnings. {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 3m 27s{color} | {color:blue} ql in master has 2307 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 3s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 24s{color} | {color:blue} Maven dependency ordering for patch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 1m 30s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 14s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 14s{color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} checkstyle {color} | {color:red} 0m 10s{color} | {color:red} common: The patch generated 3 new + 0 unchanged - 0 fixed = 3 total (was 0) {color} | | {color:red}-1{color} | {color:red} checkstyle {color} | {color:red} 0m 35s{color} | {color:red} ql: The patch generated 1 new + 10 unchanged - 46 fixed = 11 total (was 56) {color} | | {color:green}+1{color} | {color:green} whitespace {color} | {color:green} 0m 0s{color} | {color:green} The patch has no whitespace issues. {color} | | {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 4m 20s{color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} javadoc {color} | {color:red} 0m 12s{color} | {color:red} common generated 18 new + 27 unchanged - 0 fixed = 45 total (was 27) {color} | || || || || {color:brown} Other Tests {color} || | {color:red}-1{color} | {color:red} asflicense {color} | {color:red} 0m 13s{color} | {color:red} The patch generated 1 ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black} 24m 40s{color} | {color:black} {color} | \\ \\ || Subsystem || Report/Notes || | Optional Tests | asflicense javac javadoc findbugs checkstyle compile | | uname | Linux hiveptest-server-upstream 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux | | Build tool | maven | | Personality | /data/hiveptest/working/yetus_PreCommit-HIVE-Build-15954/dev-support/hive-personality.sh | | git revision | master / 313e49f | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | checkstyle | http://104.198.109.242/logs//PreCommit-HIVE-Build-15954/yetus/diff-checkstyle-common.txt | | checkstyle | http://104.198.109.242/logs//PreCommit-HIVE-Build-15954/yetus/diff-checkstyle-ql.txt | | javadoc | http://104.198.109.242/logs//PreCommit-HIVE-Build-15954/yetus/diff-javadoc-javadoc-common.txt | | asflicense | http://104.198.109.242/logs//PreCommit-HIVE-Build-15954/yetus/patch-asflicense-problems.txt | | modules | C: common ql U: . | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-15954/yetus.txt | | Powered by | Apache Yetus http://yetus.apache.org | This message was automatically generated. > CombineHiveInputFormat Thread Pool Sizing > ----------------------------------------- > > Key: HIVE-21210 > URL: https://issues.apache.org/jira/browse/HIVE-21210 > Project: Hive > Issue Type: Improvement > Affects Versions: 4.0.0, 3.2.0 > Reporter: BELUGA BEHR > Assignee: BELUGA BEHR > Priority: Major > Attachments: HIVE-21210.1.patch, HIVE-21210.2.patch, > HIVE-21210.3.patch, HIVE-21210.4.patch > > > Threadpools. > Hive uses threadpools in several different places and each implementation is > a little different and requires different configurations. I think that Hive > needs to reign in and standardize the way that threadpools are used and > threadpools should scale automatically without manual configuration. At any > given time, there are many hundreds of threads running in the HS2 as the > number of simultaneous connections increases and they surely cause contention > with one-another. > Here is an example: > {code:java|title=CombineHiveInputFormat.java} > // max number of threads we can use to check non-combinable paths > private static final int MAX_CHECK_NONCOMBINABLE_THREAD_NUM = 50; > private static final int DEFAULT_NUM_PATH_PER_THREAD = 100; > {code} > When building the splits for a MR job, there are up to 50 threads running per > query and there is not much scaling here, it's simply 1 thread : 100 files > ratio. This implies that to process 5000 files, there are 50 threads, after > that, 50 threads are still used. Many Hive jobs these days involve more than > 5000 files so it's not scaling well on bigger sizes. > This is not configurable (even manually), it doesn't change when the hardware > specs increase, and 50 threads seems like a lot when a service must support > up to 80 connections: > [https://www.cloudera.com/documentation/enterprise/5/latest/topics/admin_hive_tuning.html] > Not to mention, I have never seen a scenario where HS2 is running on a host > all by itself and has the entire system dedicated to it. Therefore it should > be more friendly and spin up fewer threads. > I am attaching a patch here that provides a few features: > * Common module that produces {{ExecutorService}} which caps the number of > threads it spins up at the number of processors a host has. Keep in mind that > a class may submit as much work units ({{Callables}} as they would like, but > the number of threads in the pool is capped. > * Common module for partitioning work. That is, allow for a generic > framework for dividing work into partitions (i.e. batches) > * Modify {{CombineHiveInputFormat}} to take advantage of both modules, > performing its same duties in a more Java OO way that is currently implemented > * Add a partitioning (batching) implementation that enforces partitioning of > a {{Collection}} based on the natural log of the {{Collection}} size so that > it scales more slowly than a simple 1:100 ratio. > * Simplify unit test code for {{CombineHiveInputFormat}} > My hope is to introduce these tools to {{CombineHiveInputFormat}} and then to > drop it into other places. One of the things I will introduce here is a > "direct thread" {{ExecutorService}} so that even if there is a configuration > for a thread pool to be disabled, it will still use an {{ExecutorService}} so > that the project can avoid logic like "if this function is services by a > thread pool, use a {{ExecutorService}} (and remember to close it later!) > otherwise, create a single thread" so that things like [HIVE-16949] can be > avoided in the future. Everything will just use an {{ExecutorService}}. -- This message was sent by Atlassian JIRA (v7.6.3#76005)