I think Netty4 requires more offheap memory. you might need to tune the JVM settings. I doubt that latency diff coming from the JVM gc.
A simple thing to verify that is to dump the gc log by adding " -Xloggc:" setting and compare the gc logs between versions. - Sijie On Tue, Jul 11, 2017 at 12:16 AM, Enrico Olivelli <eolive...@gmail.com> wrote: > a did a bisect and the culprit (in my opinion) is the switch to netty 4 for > the performance regression from 4.5 and 4.4 > > at commit: > commit 811ece53a1c975c4e768422f3d622ac9de6b3e41 BOOKKEEPER-1058: Ignore > already deleted ledger on replication audit > > Total time: 204 ms > Total real time: 79 ms per entry > > at commit: > commit 74f795136c1fff3badb29fc982d0cc2d43096b45 BOOKKEEPER-1008: Netty 4.1 > > Total time: 308 ms > Total real time: 189 ms per entry > > I have tried with epoll and with local transport, results does not change. > I tried to upgrade to netty 4.1.13 too, but no change > > Could it be the memory allocator of netty which is overwhelmed with sudden > bursts of allocation ? > I did some trial with UnpooledByteBufAllocator.DEFAULT and it helps a > little, we get to "110 ms per entry" vs "189 ms per entry" > > the bench is here: > https://github.com/eolivelli/bookkeepers-benchs/blob/master/src/test/java/ > BookKeeperWriteTest.java > > > -- Enrico > > > > 2017-07-10 19:46 GMT+02:00 Enrico Olivelli <eolive...@gmail.com>: > > > > > > > Il lun 10 lug 2017, 18:21 Venkateswara Rao Jujjuri <jujj...@gmail.com> > ha > > scritto: > > > >> With Netty changes, lack of native epoll() has huge perf impact as per > >> Kishore. > >> Are you sure you are using epoll()? > >> > > > > Yes. I tried with netty local transport too. It seems not related to > netty > > to me. > > I will double check, tomorrow > > Enrico > > > > > >> On Mon, Jul 10, 2017 at 1:49 AM, Enrico Olivelli <eolive...@gmail.com> > >> wrote: > >> > >> > 2017-07-10 10:40 GMT+02:00 Sijie Guo <guosi...@gmail.com>: > >> > > >> > > 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" <guosi...@gmail.com> 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" <eolive...@gmail.com> > >> > 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 > >> > > -- > > > > > > -- Enrico Olivelli > > >
