On Mon, Feb 22, 2016 at 3:03 PM, Colin P. McCabe <[email protected]> wrote:
> There are at least 3 RPC compatibility-breaking changes in > htrace-htraced between 4.0.1 and 4.1.0: > > HTRACE-315 changed the default port for htraced's HTTP interface from > 9095 to 9096. > HTRACE-237 changes the HTTP wire format slightly for htraced. > Previous to this, we just sent a whitespace-separated list of trace > spans. After this, we send an actual JSON object. > HTRACE-308 (Deserialize WriteSpans requests incrementally rather than > all at once) changes the field "Spans" in the HRPC header to > "NumSpans". It also decreases the maximum RPC size, > MAX_HRPC_BODY_LENGTH, from 64 MB to 32 MB. > > Thanks Colin. > To be honest, the main point of 4.0.1 was to stabilize the > htrace-core4 API and make a first release with the GUI. There was a > lot of unfinished business in htraced-- things that we only got to > 4.1. htraced is way more stable in 4.1 since we dealt with things > like GC pressure, the client side, and so forth. And also just fixing > bugs. I think we should accept the compatibility break with 4.0.1. > However, I agree that it would be nice to support the "old client, new > server" case. I filed HTRACE-344 to add a mechanism that makes it > easier to detect the case where the client is too new, and give back a > reasonable response. I don't think we should adopt a formal > compatibility policy-- htraced is not mature enough for that. But we > can strive to maintain compatibility harder than we have in 4.2 (or > whatever the next release ends up being.) > > Ok. Thats good enough I'd say. +1 on the 4.1 RC. I checked hash and signature. Built from src and all unit tests passed. Started up htraced and put in a few spans with the client. St.Ack > best, > Colin > > > On Mon, Feb 22, 2016 at 10:37 AM, Stack <[email protected]> wrote: > > On Mon, Feb 22, 2016 at 9:51 AM, Colin P. McCabe <[email protected]> > wrote: > > > >> On Sun, Feb 21, 2016 at 8:10 PM, Stack <[email protected]> wrote: > >> > "The rationale for this limitation is that tracing can simply be > disabled > >> > for a brief period during the rolling upgrade process." > >> > > >> > The second time an operator has to do this, they'll just throw away > >> tracing > >> > as a PITA. > >> > >> Let's put this in perspective. Apache Spark recently transitioned > >> from Scala 2.10 to 2.11. Those Scala releases aren't binary > >> compatible. They aren't even source-code compatible, which means that > >> people potentially had to rewrite their Spark jobs just to perform an > >> upgrade... let alone have things continue to work during the upgrade. > >> And people didn't throw away Spark; it's more popular than ever. > >> > >> > > By 'perspective', you mean others made a mess so we can too? > > > > > > > >> Now: It makes sense for a storage system (particularly a mature and > >> widely-deployed one) to bend over backwards to stay up during > >> upgrades. That's why HDFS is so strict about this, and HBase as well. > >> But they weren't always that strict; we used to break RPC > >> compatibility with every release in the earlier days. Also, HTrace is > >> not a storage system! It's a tracing system. It can be unavailable > >> for a few hours. It will be OK. > >> > >> What's not OK is for us to have CLASSPATH conflicts within a minor > >> version of htrace-core4 that will create problems during rolling > >> upgrades. It is not OK to remove APIs in htrace-core4, and so forth > >> and so on. We thought about this stuff very carefully when coming up > >> with the compatibility policy to determine what was acceptable and > >> what was not. > >> > >> > > I'm not talking about CLASSPATH, I'm talking about the sending of spans. > > > > Do you know for sure that a 4.0.1 client can't talk to a 4.1.0-based > sink? > > If so, do you know what is broke? > > > > Thanks Colin, > > St.Ack > > > > > > > > > >> As the project matures, we can think about adopting a more generous > >> (and much more difficult to implement) compatibility policy on a > >> component-by-component basis. But currently, a lot of the components > >> are not very mature. For example, htrace-flume has seen very little > >> development. htrace-htraced is probably the most mature component, > >> but a lot of its features are new. 4.0.1 was the first release with a > >> real GUI and usable client support. Trying to implement an HDFS or > >> HBase-style compatibility policy right now would slow down development > >> greatly, for no gain. > >> > >> best, > >> Colin > >> > >> > >> > > >> > Tracing needs to bend to serve the traced systems, not the other way > >> around. > >> > > >> > A 4.0.1 can't talk to a 4.1.0? Do you know how it is broken? > >> > > >> > St.Ack > >> > > >> > > >> > On Fri, Feb 19, 2016 at 5:17 PM, Colin P. McCabe <[email protected]> > >> wrote: > >> > > >> >> Our compatibility policy (see > >> >> > >> >> > >> > http://mail-archives.apache.org/mod_mbox/htrace-dev/201509.mbox/%[email protected]%3E > >> >> ) only covers the htrace-core4 API right now. So we can guarantee > >> >> that any projects using htrace-core 4.0.1 can upgrade to htrace-core > >> >> 4.1.0 without breaking anything. (This is a more painful guarantee > >> >> than it sounds since it means we can't remove functions, only > >> >> deprecate them... And so forth.) But it's a very useful guarantee > >> >> for our downstream projects. > >> >> > >> >> However, we don't support mixing and matching versions of the > >> >> SpanReceiver client and server components. The admin has to roll out > >> >> a uniform version of those components-- for example, using htraced > >> >> 4.0.1 with htrace-htraced.jar 4.1.0 is not supported. The rationale > >> >> for this limitation is that tracing can simply be disabled for a > brief > >> >> period during the rolling upgrade process. Also, the different > >> >> SpanReceiver subprojects are at different levels of maturity, and > >> >> imposing heavy compatibility guarantees would slow down development > >> >> for no real gain. > >> >> > >> >> best, > >> >> Colin > >> >> > >> >> > >> >> On Fri, Feb 19, 2016 at 4:32 PM, Stack <[email protected]> wrote: > >> >> > Can a 4.0.1 client talk to a 4.1.0 htrace? Has it been tested? > >> >> > St.Ack > >> >> > > >> >> > On Tue, Feb 9, 2016 at 7:00 PM, Colin P. McCabe < > [email protected]> > >> >> wrote: > >> >> > > >> >> >> Hi all, > >> >> >> > >> >> >> I've posted the second release candidate for HTrace 4.1 here: > >> >> >> > >> >> >> http://people.apache.org/~cmccabe/htrace/releases/4.1.0/rc2/ > >> >> >> > >> >> >> The jars have been staged here: > >> >> >> > >> >> >> > >> https://repository.apache.org/content/repositories/orgapachehtrace-1022 > >> >> >> > >> >> >> Compared to rc1, this rc includes HTRACE-334 and HTRACE-342. > >> >> >> > >> >> >> HTrace 4.1 brings a lot of robustness improvements. There were > major > >> >> >> improvements to htraced and the web UI, as well as new metrics > added. > >> >> >> There were numerous build fixups, and we added Docker support, to > >> >> >> ensure a repeatable build. > >> >> >> > >> >> >> Check it out. The vote will run for 5 days. > >> >> >> > >> >> >> cheers, > >> >> >> Colin > >> >> >> > >> >> >> > >> >> >> Release Notes - HTrace - Version 4.1 > >> >> >> ** Bug > >> >> >> * [HTRACE-114] - Fix compilation error of htrace-hbase against > >> >> >> hbase-1.0.0 > >> >> >> * [HTRACE-238] - Change maven compiler source level to 1.7 to > >> >> >> match targetJdk > >> >> >> * [HTRACE-243] - Remove duplicate maven-assembly-plugin > >> >> >> configuration section in htrace-htraced/pom.xml > >> >> >> * [HTRACE-245] - NOTICE.txt: change "developed by The Apache > >> >> >> Software...” to "developed at The Apache Software...” > >> >> >> * [HTRACE-246] - HTrace WebApp not properly defined and > therefore > >> >> >> not packaged into .war > >> >> >> * [HTRACE-248] - HTraced should gracefully shutdown if stopped > >> >> >> * [HTRACE-249] - Script and doc on how to publish website > >> >> >> * [HTRACE-251] - Fix "mvn clean" target > >> >> >> * [HTRACE-253] - Tracer loadSamplers and loadSpanReceivers > logs > >> >> >> are too chatty > >> >> >> * [HTRACE-256] - Change the artifactId for htrace-core in > branch > >> >> >> 4.0 to be htrace-core4 > >> >> >> * [HTRACE-257] - htrace-htraced: add web symlink rather than > >> >> >> generating programmatically > >> >> >> * [HTRACE-262] - Temporarily suppress doclint for Java 8 to > >> >> >> prevent build failure > >> >> >> * [HTRACE-266] - Make the CLIENT_REST_MAX_SPANS_AT_A_TIME_KEY > >> >> >> config key more consistent with other configs > >> >> >> * [HTRACE-267] - Move owl logo licensing information from > NOTICE > >> to > >> >> >> LICENSE > >> >> >> * [HTRACE-268] - Remove Units and go-codec from LICENSE since > >> they > >> >> >> are not contained in the source release > >> >> >> * [HTRACE-272] - TracerPool must not load multiple inscance of > >> >> >> same receiver class when a simple classname is given > >> >> >> * [HTRACE-279] - Fix issues where the HTracedSpanReceiver was > >> >> >> using the wrong JSON serialization for spans and add validation to > >> >> >> htraced REST ingest path > >> >> >> * [HTRACE-280] - htraced: add metrics about total spans added > and > >> >> >> dropped per address > >> >> >> * [HTRACE-281] - htraced: add example/htraced-conf.xml > >> >> >> * [HTRACE-282] - htraced: reap spans which are older than a > >> >> >> configurable interval > >> >> >> * [HTRACE-283] - Heartbeater should wait for goroutine to > finish > >> on > >> >> >> close > >> >> >> * [HTRACE-284] - htrace-htraced, htrace-flume: do not treat > the > >> >> >> shaded version of commons-logging as provided > >> >> >> * [HTRACE-285] - htraced tool: fix query parsing and add > >> query_test > >> >> >> * [HTRACE-289] - Fix TraceEnabled, etc. logger methods for > >> >> >> conditional logging > >> >> >> * [HTRACE-294] - htraced: fix some metrics issues > >> >> >> * [HTRACE-297] - htraced: avoid serializing spans to json > unless > >> >> >> TRACE logging is enabled > >> >> >> * [HTRACE-300] - Reaper should be initialized before shards > are > >> >> >> activated > >> >> >> * [HTRACE-301] - htraced: fix unit tests that aren't waiting > for > >> >> >> spans to be written, use semaphore for WrittenSpans > >> >> >> * [HTRACE-302] - htraced: Add admissions control to HRPC to > limit > >> >> >> the number of incoming messages > >> >> >> * [HTRACE-304] - htraced: fix bug with GREATER_THAN queries > >> >> >> * [HTRACE-307] - htraced: queries sometimes return no results > >> even > >> >> >> when many results exist due to confusion in iterator usage > >> >> >> * [HTRACE-311] - htraced: Fix logging to stdout via > -Dlog.path= > >> >> >> * [HTRACE-316] - htrace-web: span.js issue: span ID string > length > >> >> >> is 32, not 36 > >> >> >> * [HTRACE-317] - Fix the documentation for adding tracing to > an > >> >> >> application to reflect HTrace 4.x API changes > >> >> >> * [HTRACE-328] - htraced continues scanning in some cases even > >> >> >> when no more results are possible > >> >> >> > >> >> >> ** Improvement > >> >> >> * [HTRACE-342] - centralize building instructions in > BUILDING.txt > >> >> >> * [HTRACE-334] - htrace-web: Make limit of search and children > >> API > >> >> >> configurable > >> >> >> * [HTRACE-129] - htraced: add /server/stats REST endpoint > >> >> >> * [HTRACE-156] - HTrace GUI: add about view > >> >> >> * [HTRACE-181] - gui: Split "about" screen > >> >> >> * [HTRACE-237] - Optimize htraced span receiver > >> >> >> * [HTRACE-239] - Add htrace/impl/TestZipkinSpanReceiver.java > >> >> >> * [HTRACE-260] - htrace-zipkin should not set the obsolete > >> >> >> duration field in thrift > >> >> >> * [HTRACE-271] - Add log4j.properties to all submodule tests > >> >> >> * [HTRACE-276] - Shade classes into org.apache.htrace.shaded > >> >> >> rather than org.apache.htrace > >> >> >> * [HTRACE-286] - htraced: improvements to logging, daemon > >> startup, > >> >> >> and configuration > >> >> >> * [HTRACE-290] - htraced: Fix per-faculty log level settings > and > >> >> >> add unit tests for conditional logging > >> >> >> * [HTRACE-291] - rename bin/htrace to bin/htracedTool > >> >> >> * [HTRACE-292] - "htracedTool version" should display the git > >> >> >> hash, and -Dgit.version option should be available for build > >> >> >> * [HTRACE-295] - htraced: setting span.expiry.ms to 0 should > >> >> >> disable span expiry > >> >> >> * [HTRACE-296] - htraced tests: make sure local settings for > >> >> >> HTRACED_WEB_DIR and HTRACE_CONF_DIR don't affect unit tests > >> >> >> * [HTRACE-298] - htraced: improve datastore serialization and > >> >> metrics > >> >> >> * [HTRACE-303] - Add client-side htraceDropped log file to > track > >> >> >> dropped spans > >> >> >> * [HTRACE-305] - htrace-web: Use greater-than-or-equal rather > >> than > >> >> >> greater-than in more places > >> >> >> * [HTRACE-306] - htraced: logs should use UTC > >> >> >> * [HTRACE-308] - Deserialize WriteSpans requests incrementally > >> >> >> rather than all at once to optimize GC > >> >> >> * [HTRACE-310] - htracedTool: when there is an error response, > >> >> >> print the body of the response > >> >> >> * [HTRACE-312] - htraced: if GOMAXPROCS is left at 1, set it > to > >> >> >> the number of CPUs > >> >> >> * [HTRACE-313] - htraced span receiver clientDropped file > should > >> >> >> include timestamps > >> >> >> * [HTRACE-314] - htraced: make datastore loading safer > >> >> >> * [HTRACE-327] - HTRACE-327: improve htraced command-line > parsing > >> >> >> and add version command > >> >> >> * [HTRACE-334] - htrace-web: Make limit of search and children > >> API > >> >> >> configurable > >> >> >> * [HTRACE-335] - htrace-web: Adjust size of span widget > >> >> >> * [HTRACE-339] - Major type in htrace-flume README > >> >> >> > >> >> >> ** New Feature > >> >> >> * [HTRACE-235] - htrace-zipkin - add Kafka transport support > >> >> >> * [HTRACE-277] - htraced: Add /server/conf endpoint to get > server > >> >> >> configuration > >> >> >> * [HTRACE-278] - htraced: dump thread stacks and GC statistics > >> >> >> when SIGQUIT is sent > >> >> >> * [HTRACE-288] - htraced: Add a user interface to view server > >> >> >> version, metrics, and configuration > >> >> >> * [HTRACE-293] - htrace-web: control-click should fully expand > >> trace > >> >> >> trees > >> >> >> * [HTRACE-299] - htraced: add /server/debugInfo REST endpoint > to > >> >> >> get stack traces and GC stats > >> >> >> * [HTRACE-309] - htraced: improve leveldb configuration > >> >> >> * [HTRACE-323] - htrace-web: change the cursor to a spinner > while > >> >> >> a search is in progress > >> >> >> * [HTRACE-332] - htraced: optionally enable leveldb LRU cache > >> >> >> > >> >> >> ** Task > >> >> >> * [HTRACE-241] - Docker image for HTrace > >> >> >> * [HTRACE-315] - htraced: change default web port from 9095 to > >> 9096 > >> >> >> * [HTRACE-319] - mark versions 4.0 and 4.0.1 as released > >> >> >> * [HTRACE-331] - create git tags for 4.0 and 4.0.1 releases > >> >> >> > >> >> >> ** Wish > >> >> >> * [HTRACE-269] - HTraceConfiguration support to get the map of > >> >> >> configurations > >> >> >> > >> >> > >> >
