ChangeLog.md

NSQ Changelog

Binaries

0.3.6 - 2015-09-24

Upgrading from 0.3.5: Binaries contain no backwards incompatible changes.

We've adopted the Contributor Covenant 1.2 Code of Conduct (#593). Help us keep NSQ open and inclusive by reading and following this document.

We closed a few longstanding issues related to nsqadmin, namely (#323, et al.) converting it to an API and single-page app (so that it is much easier to develop), displaying fine-grained errors (#421, #657), and enabling support for --tls-required configurations (#396).

For nsqd, we added support for deferred publishing aka DPUB (#293), which allows a producer to specify a duration of time to delay initial delivery of the message. We also addressed performance issues relating to large numbers of topics/channels (#577) by removing some per-channel goroutines in favor of a centralized, periodic, garbage collection approach.

In order to provide more flexibility when deploying NSQ in dynamically orchestrated topologies, nsqd now supports the ability to configure nsqlookupd peers at runtime via HTTP (#601), eliminating the need to restart the daemon.

As part of the large nsqadmin refactoring, we took the opportunity to cleanup the internals for all of the daemon's HTTP code paths (#601, #610, #612, #641) as well as improving the test suite so that it doesn't leave around temporary files (#553).

Features:

• #593 - add code of conduct
• #323/#631/#632/#642/#421/#649/#650/#651/#652/#654 - nsqadmin: convert to API / single-page app
• #653 - nsqadmin: expand notification context
• #293 - nsqd: add deferred pub (DPUB)
• #577 - nsqd: drop per-channel queue workers in favor of centralized queue GC
• #584 - nsqlookupd: improve registration DB performance (thanks @xiaost)
• #601 - nsqd: HTTP endpoints to dynamically configure nsqlookupd peers
• #608 - nsqd: support for filtering /stats to topic/channel (thanks @chrusty)
• #601/#610/#612/#641 - improved HTTP internal routing / log HTTP requests
• #628 - nsqd: clarify help text for --e2e-processing-latency-percentile
• #640 - switch --{consumer,producer}-opt to nsq.ConfigFlag

Bugs:

• #656 - nsqadmin: update statsd prefix to stats.counters
• #421/#657 - nsqadmin: display upstream/partial errors
• #396 - nsqdamin/nsqd: support for --tls-required
• #558 - don't overwrite docker root FS
• #582 - nsqd: ignore benign EOF errors
• #587 - nsqd: GUID error handling / catch errors if GUID goes backwards (thanks @mpe)
• #586 - nsqd: fix valid range for --worker-id
• #550/#602/#617/#618/#619/#620/#622 - nsqd: fix benchmarks (thanks @Dieterbe)
• #553 - cleanup test dirs
• #600 - nsqd: enforce diskqueue min/max message size (thanks @twmb)

0.3.5 - 2015-04-26

Upgrading from 0.3.3: Binaries contain no backwards incompatible changes.

This is another quick bug fix release to address the broken nsqadmin binary in the distribution (see #578).

0.3.4 - 2015-04-26

WARNING: please upgrade to v0.3.5 to address the broken nsqadmin binary.

Upgrading from 0.3.3: Binaries contain no backwards incompatible changes.

This is a quick bug fix release to fix the outdated go-nsq dependency in v0.3.3 for the bundled utilities (see 6e8504e).

0.3.3 - 2015-04-26

WARNING: please upgrade to v0.3.5 to address the outdated go-nsq dependency for the bundled utilities and the broken nsqadmin binary.

Upgrading from 0.3.2: Binaries contain no backwards incompatible changes.

This release is primarily a bug fix release after cleaning up and reorganizing the codebase. nsqadmin is now importable, which paves the way for completing #323. The bundled utilities received a few feature additions and bug fixes (mostly from bug fixes on the go-nsq side).

Features:

• #569 - nsqadmin: re-org into importable package
• #562 - nsq_to_{nsq,http}: add epsilon-greedy mode (thanks @twmb)
• #547 - nsqd: adds start_time to /stats (thanks @ShawnSpooner)
• #544 - nsq_to_http: accept any 200 response as success (thanks @mikedewar)
• #548 - nsq_to_http: read entire request body (thanks @imgix)
• #552/#554/#555/#556/#561 - code cleanup and /internal package re-org (thanks @cespare)

Bugs:

• #573 - nsqd: don't persist metadata upon startup (thanks @xiaost)
• #560 - nsqd: do not print EOF error when client closes cleanly (thanks @twmb)
• #557 - nsqd: fix --tls-required=tcp-https with --tls-client-auth-policy (thanks @twmb)
• #545 - enable shell expansion in official Docker image (thanks @paddyforan)

NOTE: the bundled utilities are built against go-nsq v1.0.4 and include all of those features/fixes.

0.3.2 - 2015-02-08

Upgrading from 0.3.1: Binaries contain no backwards incompatible changes however as of this release we've updated our official Docker images.

We now provide a single Docker image nsqio/nsq that includes all of the NSQ binaries. We did this for several reasons, primarily because the tagged versions in the previous incarnation were broken (and did not actually pin to a version!). The new image is an order of magnitude smaller, weighing in around 70mb.

In addition, the impetus for this quick release is to address a slew of reconnect related bug fixes in the utility apps (nsq_to_nsq, nsq_to_file, etc.), for details see the go-nsq v1.0.3 release notes.

Features:

• #534/#539/#540 - single Dockerfile approach (thanks @paddyforan)

Bugs:

• #529 - nsqadmin: fix more #ephemeral topic deletion issues
• #530 - nsqd: fix the provided sample config file (thanks @jnewmano)
• #538 - nsqd: fix orphaned ephemeral channels (thanks @adamsathailo)

0.3.1 - 2015-01-21

Upgrading from 0.3.0: No backwards incompatible changes.

This release contains minor bug fixes and feature additions.

There are a number of functionality improvements to the nsq_stat and nsq_to_file helper applications (and general support for #ephemeral topics, broken in 0.2.30).

Additionally, the TLS options continue to improve with support for setting --tls-min-version and a work-around for a bug relating to TLS_FALLBACK_SCSV (to be fixed in Go 1.5).

Features:

• #527 - nsq_stat: deprecate --status-every in favor of --interval
• #524 - nsq_stat: add --count option (thanks @nordicdyno)
• #518 - nsqd: set defaults for --tls-min-version and set TLS max version to 1.2
• #475/#513/#518 - nsqd: --tls-required can be disabled for HTTP / add --tls-min-version (thanks @twmb)
• #496 - nsq_to_file: add <PID> to filename and rotation by size/interval (thanks @xiaost)
• #507 - nsq_stat: add rates (thanks @xiaost)
• #505 - nsqd: speed up failure path of BytesToBase10 (thanks @iand)

Bugs:

• #522 - nsqadmin: fix #ephemeral topic deletion issues
• #509 - nsqd: fix diskqueue atomic rename on Windows (thanks @allgeek)
• #479 - nsqd: return output_buffer_* resolved settings in IDENTIFY response (thanks @tj)

0.3.0 - 2014-11-18

Upgrading from 0.2.31: No backwards incompatible changes.

This release includes a slew of bug fixes and few key feature additions.

The biggest functional change is that nsqd no longer decrements its RDY count for clients. This means that client libraries no longer have to periodically re-send RDY. For some context, nsqd already provided back-pressure due to the fact that a client must respond to messages before receiving new ones. The decremented RDY count only made the implementation of the server and client more complex without additional benefit. Now the RDY command can be treated as an "on/off" switch. For details see #404 and the associated changes in nsqio/go-nsq#83 and nsqio/pynsq#98.

The second biggest change (and oft-requested feature!) is #ephemeral topics. Their behavior mirrors that of channels. This feature is incredibly useful for situations where you're using topics to "route" messages to consumers (like RPC) or when a backlog of messages is undesirable.

There are now scripts in the bench directory that automate the process of running a distributed benchmark. This is a work-in-progress, but it already provides a closer-to-production setup and therefore more accurate results. There's much work to do here!

A whole bunch of bugs were fixed - notably all were 3rd-party contributions! Thanks!

• #305 - #ephemeral topics
• #404/#459 - don't decr RDY / send RDY before FIN/REQ
• #472 - improve nsqd diskqueue sync strategies
• #488 - ability to filter topics by regex in nsq_to_file (thanks @lxfontes)
• #438 - distributed pub-sub benchmark scripts
• #448 - better nsqd IOLoop logging (thanks @rexposadas)
• #458 - switch to gpm for builds

Bugs:

• #493 - ensure all nsqd Notify() goroutines have exited prior to shutdown (thanks @allgeek)
• #492 - ensure diskqueue syncs at end of benchmarks (thanks @Dieterbe)
• #490 - de-flake TestPauseMetadata (thanks @allgeek)
• #486 - require ports to be specified for daemons (thanks @jnewmano)
• #482 - better bash in dist.sh (thanks @losinggeneration)
• #480 - fix panic when nsqadmin checks stats for missing topic (thanks @jnewmano)
• #469 - fix panic when misbehaving client sends corrupt command (thanks @prio)
• #461 - fix panic when nsqd decodes corrupt message data (thanks @twmb)
• #454/#455 - fix 32-bit atomic ops in nsq_to_nsq/nsq_to_http (thanks @leshik)
• #451 - fix go get compatibility (thanks @adams-sarah)

0.2.31 - 2014-08-26

Upgrading from 0.2.30: No backwards incompatible changes.

This release includes a few key changes. First, we improved feedback and back-pressure when nsqd writes to disk. Previously this was asynchronous and would result in clients not knowing that their PUB had failed. Interestingly, this refactoring improved performance of PUB by 41%, by removing the topic's goroutine responsible for message routing in favor of N:N Go channel communication. For details see #437.

@paddyforan contributed official Dockerfiles that are now built automatically via Docker Hub. Please begin to use (and improve these) as the various older images we had been maintaining will be deprecated.

The utility apps deprecated the --reader-opt flag in favor of --consumer-opt and nsq_to_nsq and to_nsq received a --producer-opt flag, for configuring details of the connection publishing to nsqd. Additionally, it is now possible to configure client side TLS certificates via tls_cert and tls_key opts.

As usual, we fixed a few minor bugs, see below for details.

New Features / Enhancements:

• #422/#437 - nsqd: diskqueue error feedback/backpressure (thanks @boyand)
• #412 - official Dockerfiles for nsqd, nsqlookupd, nsqadmin (thanks @paddyforan)
• #442 - utilities: add --consumer-opt alias for --reader-opt and add --producer-opt to nsq_to_nsq (also support configuration of tls_cert and tls_key)
• #448 - nsqd: improve IOLoop error messages (thanks @rexposadas)

Bugs:

• #440 - nsqd: fixed statsd GC stats reporting (thanks @jphines)
• #434/#435 - refactored/stabilized tests and logging
• #429 - nsqd: improve handling/documentation of --worker-id (thanks @bschwartz)
• #428 - nsqd: IDENTIFY should respond with materialized msg_timeout (thanks @visionmedia)

0.2.30 - 2014-07-28

Upgrading from 0.2.29: No backwards incompatible changes.

IMPORTANT: this is a quick bug-fix release to address a panic in nsq_to_nsq and nsq_to_http, see #425.

New Features / Enhancements:

• #417 - nsqadmin/nsqd: expose TLS connection state
• #425 - nsq_to_nsq/nsq_to_file: display per-destination-address timings

Bugs:

• #425 - nsq_to_nsq/nsq_to_file: fix shared mutable state panic

0.2.29 - 2014-07-25

Upgrading from 0.2.28: No backwards incompatible changes.

This release includes a slew of new features and bug fixes, with contributions from 8 members of the community, thanks!

The most important new feature is authentication (the AUTH command for nsqd), added in #356. When nsqd is configured with an --auth-http-address it will require clients to send the AUTH command. The AUTH command body is opaque to nsqd, it simply passes it along to the configured auth daemon which responds with well formed JSON, indicating which topics/channels and properties on those entities are accessible to that client (rejecting the client if it accesses anything prohibited). For more details, see the spec or the nsqd guide.

Additionally, we've improved performance in a few areas. First, we refactored in-flight handling in nsqd to reduce garbage creation and improve baseline performance 6%. End-to-end processing latency calculations are also significantly faster, thanks to improvements in the perks package.

HTTP response formats have been improved (removing the redundant response wrapper) and cleaning up some of the endpoint namespaces. This change is backwards compatible. Clients wishing to move towards the new response format can either use the new endpoint names or send the following header:

Accept: application/vnd.nsq version=1.0

Other changes including officially bumping the character limit for topic and channel names to 64 (thanks @svmehta), making the REQ timeout limit configurable in nsqd (thanks @AlphaB), and compiling static asset dependencies into nsqadmin to simplify deployment (thanks @crossjam).

Finally, to_nsq was added to the suite of bundled apps. It takes a stdin stream and publishes to nsqd, an extremely flexible solution (thanks @matryer)!

As for bugs, they're mostly minor, see the pull requests referenced in the section below for details.

New Features / Enhancements:

• #304 - apps: added to_nsq for piping stdin to NSQ (thanks @matryer)
• #406 - nsqadmin: embed external static asset dependencies (thanks @crossjam)
• #389 - apps: report app name and version via user_agent
• #378/#390 - nsqd: improve in-flight message handling (6% faster, GC reduction)
• #356/#370/#386 - nsqd: introduce AUTH
• #358 - increase topic/channel name max length to 64 (thanks @svmehta)
• #357 - remove internal go-nsq dependencies (GC reduction)
• #330/#366 - version HTTP endpoints, simplify response format
• #352 - nsqd: make REQ timeout limit configurable (thanks @AlphaB)
• #340 - nsqd: bump perks dependency (E2E performance improvement, see 25086e4)

Bugs:

• #384 - nsqd: fix statsd GC time reporting
• #407 - nsqd: fix double TOUCH and use of client's configured msg timeout
• #392 - nsqadmin: fix HTTPS warning (thanks @juliangruber)
• #383 - nsqlookupd: fix race on last update timestamp
• #385 - nsqd: properly handle empty FIN
• #365 - nsqd: fix IDENTIFY msg_timeout response (thanks @visionmedia)
• #345 - nsq_to_file: set proper permissions on new directories (thanks @bschwartz)
• #338 - nsqd: fix windows diskqueue filenames (thanks @politician)

0.2.28 - 2014-04-28

Upgrading from 0.2.27: No backwards incompatible changes. We've deprecated the short_id and long_id options in the IDENTIFY command in favor of client_id and hostname, which more accurately reflect the data typically used.

This release includes a few important new features, in particular enhanced nsqd TLS support thanks to a big contribution by @chrisroberts.

You can now require that clients negotiate TLS with --tls-required and you can configure a client certificate policy via --tls-client-auth-policy (require or require-verify):

• require - the client must offer a certificate, otherwise rejected
• require-verify - the client must offer a valid certificate according to the default CA or the chain specified by --tls-root-ca-file, otherwise rejected

This can be used as a form of client authentication.

Additionally, nsqd is now structured such that it is importable in other Go applications via github.com/nsqio/nsq/nsqd, thanks to @kzvezdarov.

Finally, thanks to @paddyforan, nsq_to_file can now archive multiple topics or optionally archive all discovered topics (by specifying no --topic params and using --lookupd-http-address).

New Features / Enhancements:

• #334 - nsq_to_file can archive many topics (thanks @paddyforan)
• #327 - add nsqd TLS client certificate verification policy, ability to require TLS, and HTTPS support (thanks @chrisroberts)
• #325 - make nsqd importable (github.com/nsqio/nsq/nsqd) (thanks @kzvezdarov)
• #321 - improve IDENTIFY options (replace short_id and long_id with client_id and hostname)
• #319 - allow path separator in nsq_to_file filenames (thanks @jsocol)
• #324 - display memory depth and total depth in nsq_stat

Bug Fixes:

• nsqio/go-nsq#19 and nsqio/go-nsq#29 - fix deadlocks on nsq.Reader connection close/exit, this impacts the utilities packaged with the NSQ binary distribution such as nsq_to_file, nsq_to_http, nsq_to_nsq and nsq_tail.
• #329 - use heartbeat interval for write deadline
• #321/#326 - improve benchmarking tests
• #315/#318 - fix test data races / flakiness

0.2.27 - 2014-02-17

Upgrading from 0.2.26: No backwards incompatible changes. We deprecated --max-message-size in favor of --max-msg-size for consistency with the rest of the flag names.

IMPORTANT: this is another quick bug-fix release to address an issue in nsqadmin where templates were incompatible with older versions of Go (pre-1.2).

• #306 - fix nsqadmin template compatibility (and formatting)
• #310 - fix nsqadmin behavior when E2E stats are disabled
• #309 - fix nsqadmin INVALID_ERROR on node page tombstone link
• #311/#312 - fix nsqd client metadata race condition and test flakiness
• #314 - fix nsqd test races (run w/ -race and GOMAXPROCS=4) deprecate --max-message-size

0.2.26 - 2014-02-06

Upgrading from 0.2.25: No backwards incompatible changes.

IMPORTANT: this is a quick bug-fix release to address a regression identified in 0.2.25 where statsd prefixes were broken when using the default (or any) prefix that contained a %s for automatic host replacement.

• #303 - fix nsqd --statsd-prefix when using %s host replacement

0.2.25 - 2014-02-05

Upgrading from 0.2.24: No backwards incompatible changes.

This release adds several commonly requested features.

First, thanks to @elubow you can now configure your clients to sample the stream they're subscribed to. To read more about the details of the implementation see #286 and the original discussion in #223. Eric also contributed an improvement to nsq_tail to add the ability to tail the last N messages and exit.

We added config file support (TOML) for nsqd, nsqlookupd, and nsqadmin - providing even more deployment flexibility. Example configs are in the contrib directory. Command line arguments override the equivalent option in the config file.

We added the ability to pause a topic (it is already possible to pause individual channels). This functionality stops all message flow from topic to channel for all channels of a topic, queueing at the topic level. This enables all kinds of interesting possibilities like atomic channel renames and trivial infrastructure wide operations.

Finally, we now compile the static assets used by nsqadmin into the binary, simplifying deployment. This means that --template-dir is now deprecated and will be removed in a future release and you can remove the templates you previously deployed and maintained.

New Features / Enhancements:

• #286 - add client IDENTIFY option to sample a % of messages
• #279 - add TOML config file support to nsqd, nsqlookupd, and nsqadmin
• #263 - add ability to pause a topic
• #291 - compile templates into nsqadmin binary
• #285/#288 - nsq_tail support for -n # to get recent # messages
• #287/#294 - display client IDENTIFY attributes in nsqadmin (sample rate, TLS, compression)
• #189/#296 - add client user agent to `nsqadmin``
• #297 - add nsq_to_nsq JSON message filtering options

0.2.24 - 2013-12-07

Upgrading from 0.2.23: No backwards incompatible changes. However, as you'll see below, quite a few command line flags to the utility apps (nsq_to_http, nsq_to_file, nsq_to_http) were deprecated and will be removed in the next release. Please use this release to transition over to the new ones.

NOTE: we are now publishing additional binaries built against go1.2

The most prominent addition is the tracking of end-to-end message processing percentiles. This measures the amount of time it's taking from PUB to FIN per topic/channel. The percentiles are configurable and, because there is some overhead in collecting this data, it can be turned off entirely. Please see the section in the docs for implementation details.

Additionally, the utility apps received comprehensive support for all configurable reader options (including compression, which was previously missing). This necessitated a bit of command line flag cleanup, as follows:

nsq_to_file

• deprecated --gzip-compression in favor of --gzip-level
• deprecated --verbose in favor of --reader-opt=verbose

nsq_to_http

• deprecated --throttle-fraction in favor of --sample
• deprecated --http-timeout-ms in favor of --http-timeout (which is a duration flag)
• deprecated --verbose in favor of --reader-opt=verbose
• deprecated --max-backoff-duration in favor of --reader-opt=max_backoff_duration=X

nsq_to_nsq

• deprecated --verbose in favor of --reader-opt=verbose
• deprecated --max-backoff-duration in favor of --reader-opt=max_backoff_duration=X

New Features / Enhancements:

• #280 - add end-to-end message processing latency metrics
• #267 - comprehensive reader command line flags for utilities

0.2.23 - 2013-10-21

Upgrading from 0.2.22: No backwards incompatible changes.

We now use godep in order to achieve reproducible builds with pinned dependencies. If you're on go1.1+ you can now just use godep get github.com/nsqio/nsq/....

This release includes nsqd protocol compression feature negotiation. Snappy and Deflate are supported, clients can choose their preferred format.

--statsd-prefix can now be used to modify the prefix for the statsd keys generated by nsqd. This is useful if you want to add datacenter prefixes or remove the default host prefix.

Finally, this release includes a "bug" fix that reduces CPU usage for nsqd with many clients by choosing a more reasonable default for a timer used in client output buffering. For more details see #236.

New Features / Enhancements:

• #266 - use godep for reproducible builds
• #229 - compression (Snappy/Deflate) feature negotiation
• #241 - binary support for HTTP /mput
• #269 - add --statsd-prefix flag

Bug Fixes:

• #278 - fix nsqd race for client subscription cleanup (thanks @simplereach)
• #277 - fix nsqadmin counter page
• #275 - stop accessing simplejson internals
• #274 - nsqd channel pause state lost during unclean restart (thanks @hailocab)
• #236 - reduce "idle" CPU usage by 90% with large # of clients

0.2.22 - 2013-08-26

Upgrading from 0.2.21: message timestamps are now officially nanoseconds. The protocol docs always stated this however nsqd was actually sending seconds. This may cause some compatibility issues for client libraries/clients that were taking advantage of this field.

This release also introduces support for TLS feature negotiation in nsqd. Clients can optionally enable TLS by using the appropriate handshake via the IDENTIFY command. See #227.

Significant improvements were made to the HTTP publish endpoints and in flight message handling to reduce GC pressure and eliminate memory abuse vectors. See #242, #239, and #245.

This release also includes a new utility nsq_to_nsq for performant, low-latency, copying of an NSQ topic over the TCP protocol.

Finally, a whole suite of debug HTTP endpoints were added (and consolidated) under the /debug/pprof namespace. See #238, #248, and #252. As a result nsqd now supports direct profiling via Go's pprof tool, ie:

$ go tool pprof --web http://ip.address:4151/debug/pprof/heap

New Features / Enhancements:

• #227 - TLS feature negotiation
• #238/#248/#252 - support for more HTTP debug endpoints
• #256 - nsqadmin single node view (with GC/mem graphs)
• #255 - nsq_to_nsq utility for copying a topic over TCP
• #230 - nsq_to_http takes --content-type flag (thanks @michaelhood)
• #228 - nsqadmin displays tombstoned topics in the /nodes list
• #242/#239/#245 - reduced GC pressure for inflight and /mput

Bug Fixes:

• #260 - tombstone_topic_producer action in nsqadmin missing node info
• #244 - fix 64bit atomic alignment issues on 32bit platforms
• #251 - respect configured limits for HTTP publishing
• #247 - publish methods should not allow 0 length messages
• #231/#259 - persist nsqd metadata on topic/channel changes
• #237 - fix potential memory leaks with retained channel references
• #232 - message timestamps are now nano
• #228 - nsqlookupd/nsqadmin would display inactive nodes in /nodes list
• #216 - fix edge cases in nsq_to_file that caused empty files

0.2.21 - 2013-06-07

Upgrading from 0.2.20: there are no backward incompatible changes in this release.

This release introduces a significant new client feature as well as a slew of consistency and recovery improvements to diskqueue.

First, we expanded the feature negotiation options for clients. There are many cases where you want different output buffering semantics from nsqd to your client. You can now control both output buffer size and the output buffer timeout via new fields in the IDENTIFY command. You can even disable output buffering if low latency is a priority.

You can now specify a duration between fsyncs via --sync-timeout. This is a far better way to manage when the process fsyncs messages to disk (vs the existing --sync-every which is based on # of messages). --sync-every is now considered a deprecated option and will be removed in a future release.

Finally, 0.2.20 introduced a significant regression in #176 where a topic would not write messages to its channels. It is recommended that all users running 0.2.20 upgrade to this release. For additional information see #217.

New Features / Enhancements:

• #214 - add --sync-timeout for time based fsync, improve when diskqueue syncs
• #196 - client configurable output buffering
• #190 - nsq_tail generates a random #ephemeral channel

Bug Fixes:

• #218/#220 - expose --statsd-interval for nsqadmin to handle non 60s statsd intervals
• #217 - fix new topic channel creation regression from #176 (thanks @elubow)
• #212 - dont use port in nsqadmin cookies
• #214 - dont open diskqueue writeFile with O_APPEND
• #203/#211 - diskqueue depth accounting consistency
• #207 - failure to write a heartbeat is fatal / reduce error log noise
• #206 - use broadcast address for statsd prefix
• #205 - cleanup example utils exit

0.2.20 - 2013-05-13

Upgrading from 0.2.19: there are no backward incompatible changes in this release.

This release adds a couple of convenient features (such as adding the ability to empty a topic) and continues our work to reduce garbage produced at runtime to relieve GC pressure in the Go runtime.

nsqd now has two new flags to control the max value clients can use to set their heartbeat interval as well as adjust a clients maximum RDY count. This is all set/communicated via IDENTIFY.

nsqadmin now displays nsqd -> nsqlookupd connections in the "nodes" view. This is useful for visualizing how the topology is connected as well as situations where --broadcast-address is being used incorrectly.

nsq_to_http now has a "host pool" mode where upstream state will be adjusted based on successful/failed requests and for failures, upstreams will be exponentially backed off. This is an incredibly useful routing mode.

As for bugs, we fixed an issue where "fatal" client errors were not actually being treated as fatal. Under certain conditions deleting a topic would not clean up all of its files on disk. There was a reported issue where the --data-path was not writable by the process and this was only discovered after message flow began. We added a writability check at startup to improve feedback. Finally. deferred_count was being sent as a counter value to statsd, it should be a gauge.

New Features / Enhancements:

• #197 - nsqadmin nodes list improvements (show nsqd -> lookupd conns)
• #192 - add golang runtime version to daemon version output
• #183 - ability to empty a topic
• #176 - optimizations to reduce garbage, copying, locking
• #184 - add table headers to nsqadmin channel view (thanks @elubow)
• #174/#186 - nsq_to_http hostpool mode and backoff control
• #173/#187 - nsq_stat utility for command line introspection
• #175 - add nsqd --max-rdy-count configuration option
• #178 - add nsqd --max-heartbeat-interval configuration option

Bug Fixes:

• #198 - fix fatal errors not actually being fatal
• #195 - fix delete topic does not delete all diskqueue files
• #193 - fix data race in channel requeue
• #185 - ensure that --data-path is writable on startup
• #182 - fix topic deletion ordering to prevent race conditions with lookupd/diskqueue
• #179 - deferred_count as gauge for statsd
• #173/#188/#191 - fix nsqadmin counter template error; fix nsqadmin displaying negative rates

0.2.19 - 2013-04-11

Upgrading from 0.2.18: there are no backward incompatible changes in this release.

This release is a small release that introduces one major client side feature and resolves one critical bug.

nsqd clients can now configure their own heartbeat interval. This is important because as of 0.2.18 all clients (including producers) received heartbeats by default. In certain cases receiving a heartbeat complicated "simple" clients that just wanted to produce messages and not handle asynchronous responses. This gives flexibility for the client to decide how it would like behave.

A critical bug was discovered where emptying a channel would leave client in-flight state inconsistent (it would not zero) which limited deliverability of messages to those clients.

New Features / Enhancements:

• #167 - 'go get' compatibility
• #158 - allow nsqd clients to configure (or disable) heartbeats

Bug Fixes:

• #171 - fix race conditions identified testing against go 1.1 (scheduler improvements)
• #160 - empty channel left in-flight count inconsistent (thanks @dmarkham)

0.2.18 - 2013-02-28

Upgrading from 0.2.17: all V2 clients of nsqd now receive heartbeats (previously only clients that subscribed would receive heartbeats, excluding TCP producers).

Upgrading from 0.2.16: follow the notes in the 0.2.17 changelog for upgrading from 0.2.16.

Beyond the important note above regarding heartbeats this release includes nsq_tail, an extremely useful utility application that can be used to introspect a topic on the command line. If statsd is enabled (and graphite in nsqadmin) we added the ability to retrieve rates for display in nsqadmin.

We resolved a few critical issues with data consistency in nsqlookupd when channels and topics are deleted. First, deleting a topic would cause that producer to disappear from nsqlookupd for all topics. Second, deleting a channel would cause that producer to disappear from the topic list in nsqlookupd.

New Features / Enhancements:

• #131 - all V2 nsqd clients get heartbeats
• #154 - nsq_tail example reader
• #143 - display message rates in nsqadmin

Bug Fixes:

• #148 - store tombstone data per registration in nsqlookupd
• #153 - fix large graph formulas in nsqadmin
• #150/#151 - fix topics disappearing from nsqlookupd when channels are deleted

0.2.17 - 2013-02-07

Upgrading from 0.2.16: IDENTIFY and SUB now return success responses (they previously only responded to errors). The official Go and Python libraries are forwards/backwards compatible with this change however 3rd party client libraries may not be.

Upgrading from 0.2.15: in #132 deprecations in SUB were removed as well as support for the old, line oriented, nsqd metadata file format. For these reasons you should upgrade to 0.2.16 first.

New Features / Enhancements:

• #119 - add TOUCH command to nsqd
• #142 - add --broadcast-address flag to nsqd/nsqadmin (thanks @dustismo)
• #135 - atomic MPUB
• #133 - improved protocol fatal error handling and responses; IDENTIFY/SUB success responses
• #118 - switch nsqadmin actions to POST and require confirmation
• #117/#147 - nsqadmin action POST notifications
• #122 - configurable msg size limits
• #132 - deprecate identify in SUB and old nsqd metadata file format

Bug Fixes:

• #144 - empty channel should clear inflight/deferred messages
• #140 - fix MPUB protocol documentation
• #139 - fix nsqadmin handling of legacy statsd prefixes for graphs
• #138/#145 - fix nsqadmin action redirect handling
• #134 - nsqd to nsqlookupd registration fixes
• #129 - nsq_to_file gzip file versioning
• #106 - nsqlookupd topic producer tombstones
• #100 - sane handling of diskqueue read errors
• #123/#125 - fix notify related exit deadlock

0.2.16 - 2013-01-07

Upgrading from 0.2.15: there are no backward incompatible changes in this release.

However, this release introduces the IDENTIFY command (which supersedes sending metadata along with SUB) for clients of nsqd. The old functionality will be removed in a future release.

• #114 persist paused channels through restart
• #121 fix typo preventing compile of bench_reader (thanks @datastream)
• #120 fix nsqd crash when empty command is sent (thanks @michaelhood)
• #115 nsq_to_file --filename-format --datetime-format parameter and fix
• #101 fix topic/channel delete operations ordering
• #98 nsqadmin fixes when not using lookupd
• #90/#108 performance optimizations / IDENTIFY protocol support in nsqd. For a single consumer of small messages (< 4k) increases throughput ~400% and reduces # of allocations ~30%.
• #105 strftime compatible datetime format
• #103 nsq_to_http handler logging
• #102 compatibility with Go tip
• #99 nsq_to_file --gzip flag
• #95 proxy graphite requests through nsqadmin
• #93 fix nqd API response for no topics
• #92 graph rendering options
• #86 nsq_to_http Content-Length headers
• #89 gopkg doc updates
• #88 move pynsq to it's own repo
• #81/#87 reader improvements / introduced MPUB. Fix bug for mem-queue-size < 10
• #76 statsd/graphite support
• #75 administrative ability to create topics and channels

0.2.15 - 2012-10-25

• #84 fix lookupd hanging on to ephemeral channels w/ no producers
• #82 add /counter page to nsqadmin
• #80 message size benchmark
• #78 send Content-Length for nsq_to_http requests
• #57/#83 documentation updates

0.2.14 - 2012-10-19

• #77 ability to pause a channel (includes bugfix for message pump/diskqueue)
• #74 propagate all topic changes to lookupd
• #65 create binary releases

0.2.13 - 2012-10-15

• #70 deadlined nsq_to_http outbound requests
• #69/#72 improved nsq_to_file sync strategy
• #58 diskqueue metadata bug and refactoring

0.2.12 - 2012-10-10

• #63 consolidated protocol V1 into V2 and fixed PUB bug
• #61 added a makefile for simpler building
• #55 allow topic/channel names with .
• combined versions for all binaries

0.2.7 - 0.2.11

• Initial public release.

go-nsq Client Library

• #264 moved go-nsq to its own repository

pynsq Python Client Library

• #88 moved pynsq to its own repository