With Netty changes, lack of native epoll() has huge perf impact as per
Kishore.
Are you sure you are using epoll()?

On Mon, Jul 10, 2017 at 1:49 AM, Enrico Olivelli <[email protected]>
wrote:

> 2017-07-10 10:40 GMT+02:00 Sijie Guo <[email protected]>:
>
> > Also one other thing to check is the JVM settings. Do you mind sharing
> that
> > as well?
> >
> >
> this is the surefire config, I am using oracle jdk 8
>
>              <plugin>
>                 <artifactId>maven-surefire-plugin</artifactId>
>                 <version>2.20</version>
>                 <configuration>
>                     <forkCount>1</forkCount>
>                     <reuseForks>false</reuseForks>
>
> <forkedProcessTimeoutInSeconds>300</forkedProcessTimeoutInSeconds>
>                     <argLine>-Xmx2G
> -Djava.io.tmpdir=${basedir}/target</argLine>
>                 </configuration>
>             </plugin>
>
> -- Enrico
>
>
>
> > Sijie
> >
> > On Jul 10, 2017 1:17 AM, "Sijie Guo" <[email protected]> wrote:
> >
> > > I am not sure if there is any default values changed for journal
> > settings.
> > > I would suggest you testing by setting specifically the journal
> settings.
> > >
> > > Also if you can share your benchmark, that would be good for other
> people
> > > to verify.
> > >
> > > Sijie
> > >
> > > On Jul 10, 2017 12:32 AM, "Enrico Olivelli" <[email protected]>
> wrote:
> > >
> > >> Hi,
> > >> I am doing some benchmarks on BK, I see that from 4.4.0 to 4.5.0 there
> > is
> > >> something "slow" but I cannot understand what. I really hope that I am
> > >> wrong.
> > >>
> > >> I am working with writes, I will pass to reads once writes will be ok.
> > >> My problem is both on latency (time for AddComplete callback to
> > complete)
> > >> and on overall throuput.
> > >>
> > >> Actually I have two distinct problems, but working on the first
> problem
> > I
> > >> found a performance regression.
> > >> I know that talking about "slow" things it is an hard matter, so I
> will
> > >> try
> > >> do describe as much as possible all the aspects that I think are
> > relevant.
> > >>
> > >> First problem: under certain load performance (latency+throughput)
> > degrade
> > >> too much
> > >> Second problem: the first problem is more evident in 4.5.0
> > >>
> > >> Let's describe my testcase and why I am worried.
> > >> The bench issues a batch of asyncAddEntry and prints the average time
> > for
> > >> AddComplete to complete and the overall clock time.
> > >>
> > >> This is the code
> > >>
> > >> private static final byte[] TEST_DATA = new byte[35 * 1024];
> > >> private static final int testsize = 1000;
> > >>
> > >> ...... (start 1 bookie, see below)
> > >>             ClientConfiguration clientConfiguration = new
> > >> ClientConfiguration();
> > >>             clientConfiguration.setZkServers(env.getAddress());
> > >>             try (BookKeeper bk = new BookKeeper(clientConfiguration);
> > >>                 LedgerHandle lh = bk.createLedger(1, 1, 1,
> > >> BookKeeper.DigestType.CRC32, new byte[0])) {
> > >>                 LongAdder totalTime = new LongAdder();
> > >>                 long _start = System.currentTimeMillis();
> > >>                 Collection<CompletableFuture> batch = new
> > >> ConcurrentLinkedQueue<>();
> > >>                 for (int i = 0; i < testsize; i++) {
> > >>                     CompletableFuture cf = new CompletableFuture();
> > >>                     batch.add(cf);
> > >>                     lh.asyncAddEntry(TEST_DATA, new
> > >> AsyncCallback.AddCallback() {
> > >>
> > >>                         long start = System.currentTimeMillis();
> > >>
> > >>                         @Override
> > >>                         public void addComplete(int rc, LedgerHandle
> lh,
> > >> long entryId, Object ctx) {
> > >>                             long now =
> > >> System.currentTimeMillis();
> > >>                             CompletableFuture _cf =
> (CompletableFuture)
> > >> ctx;
> > >>                             if (rc == BKException.Code.OK) {
> > >>                                 _cf.complete("");
> > >>                             } else {
> > >>
> > >> _cf.completeExceptionally(BKException.create(rc));
> > >>                             }
> > >>                             totalTime.add(now - start);
> > >>                         }
> > >>                     }, cf);
> > >> //                    Thread.sleep(1);      // this is the tirgger!!!
> > >>                 }
> > >>                 assertEquals(testsize, batch.size());
> > >>                 for (CompletableFuture f : batch) {
> > >>                     f.get();
> > >>                 }
> > >>                 long _stop = System.currentTimeMillis();
> > >>                 long delta = _stop - _start;
> > >>                 System.out.println("Total time: " + delta + " ms");
> > >>                 System.out.println("Total real time: " +
> > totalTime.sum() +
> > >> " ms -> "+(totalTime.sum()/testsize)+" ms per entry");
> > >>             }
> > >>
> > >> Bookie config:
> > >>         ServerConfiguration conf = new ServerConfiguration();
> > >>         conf.setBookiePort(5621);
> > >>         conf.setUseHostNameAsBookieID(true);
> > >>
> > >>         Path targetDir = path.resolve("bookie_data");
> > >>         conf.setZkServers("localhost:1282");
> > >>         conf.setLedgerDirNames(new
> > >> String[]{targetDir.toAbsolutePath().toString()});
> > >>         conf.setJournalDirName(targetDir.toAbsolutePath().
> toString());
> > >>         conf.setFlushInterval(1000);
> > >>         conf.setJournalFlushWhenQueueEmpty(true);
> > >>         conf.setProperty("journalMaxGroupWaitMSec", 0);
> > >>         conf.setProperty("journalBufferedWritesThreshold", 1024);
> > >>         conf.setAutoRecoveryDaemonEnabled(false);
> > >>         conf.setEnableLocalTransport(true);
> > >>         conf.setAllowLoopback(true);
> > >>
> > >> The tests starts one ZK server + 1 Bookie + the testcase in a JUnit
> test
> > >>
> > >>
> > >> Results:
> > >> A - BK-4.4.0:
> > >> Total time: 209 ms
> > >> Total real time: 194337 ms -> 194 ms per entry
> > >>
> > >> B - BK-4.5.0-SNAPSHOT:
> > >> Total time: 269 ms
> > >> Total real time: 239918 ms -> 239 ms per entry
> > >>
> > >> C - BK-4.4,0 with sleep(1):
> > >> Total time: 1113 ms (1000 ms sleep time)
> > >> Total real time: 4238 ms  -> 4 ms per entry
> > >>
> > >> D - BK-4.5,0-SNAPSHOT with sleep(1):
> > >> Total time: 1121 ms (1000 ms sleep time)
> > >> Total real time: 8018 ms -> 8 ms per entry
> > >>
> > >> Problem 1 (unexpected performance degradation):
> > >> Times per entry (latency) are incredibly slow in cases A and B.
> > >> If I add a sleep(1) between one call of asyncAddEntry and the next
> > >> "latency" is around 4 ms per entry.
> > >>
> > >> Problem 2: worse performance on 4.5.0
> > >> Compare A vs B and C vs D, it is self-explaining.
> > >>
> > >> I am running the test on my laptop, with linux 64bit (Fedora), 12 GB
> > RAM,
> > >> no swap, on an SSD disk. The results are similar on other computers.
> > >>
> > >> It seems that if I issue too many addEntry the systems slows down.
> > >>
> > >> Please note this fact:
> > >> numbers for case A and B (without sleep) mean that all the adds got
> > >> completed almost together
> > >>
> > >> for the 4.5 vs 4.4 case:
> > >> I tried to disable all of the threadpool enhancements (different
> > >> read/write
> > >> pools)....it makes not difference
> > >>
> > >> Questions:
> > >>
> > >> Is the "grouping" logic of the journal ?
> > >>
> > >> Is there a way of making a burst of 1000 async writes on the same
> ledger
> > >> perform <10 ms latency ?  (in my real case I have bursts of concurrent
> > >> writes from different threads)
> > >>
> > >> Why 4.5.0 is anyway slower ?
> > >>
> > >> Thanks
> > >>
> > >> -- Enrico
> > >>
> > >
> >
>



-- 
Jvrao
---
First they ignore you, then they laugh at you, then they fight you, then
you win. - Mahatma Gandhi

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