Changelog — com.novemberain/langohr 5.5.0

langohr.http/close-all-connections is a new function that closes all client connections on the target nodes. This is primarily useful in integration tests and certain monitoring scenarios.

Corrected Arity of `langohr.http/get-node`

Correct a typo in langohr.http/get-node that made the "short arity" version fail.

GitHub issue: #101.

langohr.core/connect now support hostname verification via the new :verify-hostname option (a boolean). Hostname verification is one part of TLS peer verification supported by RabbitMQ Java client and now Langohr.

GitHub issue: #100.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 5.9.x.

Changes between Langohr 5.0.0 and 5.1.0 (January 14th, 2019)

Clojure Dependency Update

Langohr now depends on Clojure 1.10.0 by default.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 5.5.x.

Changes between Langohr 4.2.0 and 5.0.0 (March 21st, 2018)

This release includes breaking public API changes.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 5.x.

JDK 8 is Now Required

RabbitMQ Java client 5.x requires JDK 8. It's a good chance to drop support for older JDKs in Langohr. Langohr 4.x continues to use a JDK 6 and 7-compatible version of the Java client.

Queueing/Blocking Consumers are Removed

RabbitMQ Java client 5.0 removed a long deprecated queueing consumer abstraction that used an internal j.u.c queue for deliveries and acted as an iterator. That consumer implementation never supported automatic connection recovery and isn't necessary with modern consumer operation dispatch pool.

Langohr follows suit and removes the following functions based on the QueueingConsumer:

langohr.basic/blocking-subscribe
langohr.consumers/create-queueing
langohr.consumers/deliveries-seq

langohr.consumers/deliveries-seq may be reintroduced in the future if a reasonable imlementation for it comes to mind/is contributed.

clj-http Upgrade

clj-http dependency has been updated to 3.8.x.

Changes between Langohr 4.1.0 and 4.2.0 (December 27th, 2017)

Type Hinting Improvements

Deleted a redundant type hint.

Contributed by Michal Masztalski.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 4.4.1.

clj-http Upgrade

clj-http dependency has been updated to 3.7.0.

Cheshire Upgrade

Cheshire dependency has been updated to 5.8.0.

Changes between Langohr 4.0.0 and 4.1.0 (July 23rd, 2017)

clj-http Upgrade

clj-http dependency has been updated to 3.6.0.

Cheshire Upgrade

Cheshire dependency has been updated to 5.7.1.

Changes between Langohr 3.7.0 and 4.0.0 (May 15th, 2017)

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 4.0.0.

clj-http Upgrade

clj-http dependency has been updated to 3.5.0.

Changes between Langohr 3.6.1 and 3.7.0 (December 9th, 2016)

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.6.6.

clj-http Upgrade

clj-http dependency has been updated to 3.4.1.

Cheshire Upgrade

Cheshire dependency has been updated to 5.6.3.

Changes between Langohr 3.5.x and 3.6.1 (June 18th, 2016)

Client-Provided Connection Name

:connection-name is a new connection option supported by Langohr 3.6.0 and RabbitMQ server 3.6.2 or later. It can be used to set a client- or application-specific connection name that will be displayed in the management UI.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.6.2.

clj-http Upgrade

clj-http dependency has been updated to 3.1.0.

Cheshire Upgrade

Cheshire dependency has been updated to 5.6.1.

Changes between Langohr 3.5.x and 3.5.1 (Feb 5th, 2016)

API reference corrections.

GH issue: #79.

Changes between Langohr 3.4.x and 3.5.0 (Jan 13th, 2016)

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.6.0.

Changes between Langohr 3.4.1 and 3.4.2

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.5.7.

Changes between Langohr 3.3.x and 3.4.0

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.5.6.

Changes between Langohr 3.2.x and 3.3.0

Forgiving Exception Handler by Default

Langohr now uses Java client's forgiving exception handler by default. This means unhandled consumer exceptions won't result in channel closure.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.5.4.

clj-http Upgrade

clj-http dependency has been updated to 2.0.0.

This version of clj-http bumps Apache HTTP client version to 4.5. If this is undesirable for your project, you can exclude Langohr's dependency on clj-http and use another version.

See Langohr's project.clj (the cljhttp076 profile).

Cheshire Upgrade

Cheshire dependency has been updated to 5.5.0.

Changes between Langohr 3.1.x and 3.2.0

Authentication Mechanism Support

Langohr now converts :authentication-mechanism option to a SASL mechanism. Two values are supported:

"PLAIN"
"EXTERNAL"

Contributed by Tap.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.5.2.

clj-http Upgrade

clj-http dependency has been updated to 1.1.1.

Changes between Langohr 3.0.0 and 3.1.0

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.4.4.

It includes an important binding recovery bug fix.

clj-http Upgrade

clj-http dependency has been updated to 1.0.1.

Cheshire Upgrade

Cheshire dependency has been updated to 5.4.0.

langohr.consumers/blocking-subscribe No Longer Fails

langohr.consumers/blocking-subscribe no longer fails with a function arity exception.

GH issue: #65.

Changes between Langohr 2.11.x and 3.0.0

Options as Maps

Functions that take options now require a proper Clojure map instead of pseudo keyword arguments:

;; in Langohr 2.x

(lq/declare ch q :durable true)
(lhcons/subscribe ch q (fn [_ _ _])
                        :consumer-tag ctag :handle-cancel-ok (fn [_]))
(lb/publish ch "" q "a message" :mandatory true)

;; in Langohr 3.x
(lq/declare ch q {:durable true})
(lhcons/subscribe ch q (fn [_ _ _])
                        {:consumer-tag ctag :handle-cancel-ok (fn [_])})
(lb/publish ch "" q "a message" {:mandatory true})

JDK 8 Compatibility

Langohr test suite now passes on JDK 8 (previously there was 1 failure in recovery test).

GH issue: #54.

Connection Recovery Performed by Java Client

Langohr no longer implements automatic connection recovery of its own. The feature is still there and there should be no behaviour changes but the functionality has now been pushed "upstream" in the Java client, so Langohr now relies on it to do all the work.

There is two public API changes:

com.novemberain.langohr.Recoverable is gone, langohr.core/on-recovery now uses com.rabbitmq.client.Recoverable instead in its signature.
Server-named queues will change after recovery. Use langohr.core/on-queue-recovery to register a listener for queue name change.

GH issue: #58.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.4.2.

Custom Exception Handlers

langohr.core/exception-handler is a function that customizes default exception handler RabbitMQ Java client uses:

(require '[langohr.core :as rmq])

(let [(rmq/exception-handler :handle-consumer-exception-fn (fn [ch ex consumer
                                                               consumer-tag method-name]
                                                             ))]
  )

Valid keys are:

:handle-connection-exception-fn
:handle-return-listener-exception-fn
:handle-flow-listener-exception-fn
:handle-confirm-listener-exception-fn
:handle-blocked-listener-exception-fn
:handle-consumer-exception-fn
:handle-connection-recovery-exception-fn
:handle-channel-recovery-exception-fn
:handle-topology-recovery-exception-fn

GH issue: #47.

Clojure 1.7 Support

Clojure 1.7-specific compilation issues and warnings were eliminated.

clj-http Upgrade

clj-http dependency has been updated to 1.0.0.

ClojureWerkz Support Upgrade

clojurewerkz/support dependency has been updated to 1.1.0.

langohr.core/version is Removed

langohr.core/version was removed.

Changes between Langohr 2.10.x and 2.11.0

Multi-Host Support In langohr.core/connect

langohr.core/connect now supports :hosts as well as :host. The hosts provided will be iterated over, the first reachable host will be used.

Example:

(require '[langohr.core :as rmq])

(rmq/connect {:hosts #{"192.168.1.2" "192.168.1.3"}})
;; uses port 5688 for both hosts
(rmq/connect {:hosts #{"192.168.1.2" "192.168.1.3"} :port 5688})
;; uses multiple host/port pairs
(rmq/connect {:hosts #{["192.168.1.2" 5688] ["192.168.1.3" 5689]}})

Changes between Langohr 2.9.x and 2.10.0

Retries for all IOExceptions During Recovery

All IOException subclasses thrown during connection recovery attempts will now be retried.

Contributed by Paul Bellamy (Xively).

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.3.1.

Changes between Langohr 2.8.x and 2.9.0

Configurable Default and Per-Operation Options in HTTP API Client

Most HTTP API client functions now have an additional optional arguments, which is a map of options passed to clj-http functions. This lets you fine tune certain HTTP requests as needed.

In addition, langohr.http/connect! now accepts one more argument which serves as default HTTP client options merged with the options provided per langohr.http function call:

(require '[langohr.http :as hc])

;; non-20x/30x statuses will now throw exceptions
(hc/connect! "http://127.0.0.1:15673" "guest" "guest" {:throw-exceptions true})

;; disable throwing exceptions for an individual operation,
;; because 404 is an expected HTTP response in this case
(hc/vhost-exists? "myapp-production" {:throw-exceptions false})
;= false

;; disabling peer verification for HTTPS requests
(hc/connect! "http://127.0.0.1:15673" "guest" "guest" {:insecure? true})

Thread Factory Customization

It is now possible to customize a java.util.concurrent.ThreadFactory used by Langohr connections. The factory will be used to instantiate all threads created by the client under the hood.

The primary use case for this is running on Google App Engine which prohibits direct thread instantiation and requires apps to use thread manager (or thread factory) from GAE SDK instead.

To provide a custom thread factory, pass it as :thread-factory to langohr.core/connect. To reify a thread factory with a Clojure function, use langohr.core/thread-factory-from:

(require '[langohr.core :as lc])

(let [tf (lc/thread-factory-from
            (fn [^Runnable r]
              (Thread. r)))]
  (lc/connect {:thread-factory tf}))

com.rabbitmq.client.TopologyRecoveryException is Used

Langohr now uses com.rabbitmq.client.TopologyRecoveryException instead of reinventing its own exception to indicate topology recovery failure.

RabbitMQ Java Client Compatibility

A few RabbitMQ Java client interface compatibility issues are resolved.

Changes between Langohr 2.7.x and 2.8.0

Client-side Channel Flow Removed

langohr.channel/flow and langohr.channel/flow? were removed. Client-side flow control has been deprecated for a while and was removed in RabbitMQ Java client 3.3.0.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.3.0.

Clojure 1.6 By Default

Langohr now depends on org.clojure/clojure version 1.6.0. It is still compatible with Clojure 1.4 and if your project.clj depends on a different version, it will be used, but 1.6 is the default now.

We encourage all users to upgrade to 1.6, it is a drop-in replacement for the majority of projects out there.

langohr.http/protocol-ports

langohr.http/protocol-ports is a new function that returns a map of protocol names to protocol ports. The protocols are listed with langohr.http/list-enabled-protocols.

Changes between Langohr 2.6.x and 2.7.1

langohr.http/list-enabled-protocols

langohr.http/list-enabled-protocols is a new function that lists the protocols a RabbitMQ installation supports, e.g. "amqp" or "mqtt". Note that this currently does not include WebSTOMP (due to certain technical decisions in RabbitMQ Web STOMP plugin).

Changes between Langohr 2.5.x and 2.6.0

langohr.http/list-connections-from, /close-connections-from

langohr.http/list-connections-from and langohr.http/close-connections-from are two new functions that list and close connections for a given username, respectively:

(require '[langohr.http :as hc])

(hc/list-connections-from "guest")
;= a list of connections with username "guest"

;; closes all connections from "guest"
(hc/close-connections-from "guest")

clj-http Upgrade

clj-http dependency has been updated to 0.9.0.

Changes between Langohr 2.3.x and 2.5.0

langohr.http/declare-user Renamed

langohr.http/declare-user was renamed to langohr.http/set-user.

langohr.http/declare-policy Renamed

langohr.http/declare-policy was renamed to langohr.http/set-policy.

langohr.http/declare-permissions Renamed

langohr.http/declare-permissions was renamed to langohr.http/set-permissions.

langohr.http/declare-user Renamed

langohr.http/declare-user was renamed to langohr.http/add-user.

langohr.http/vhost-exists?

langohr.http/vhost-exists? is a new function that returns true if provided vhost exists:

(require '[langohr.http :as hc])

(hc/vhost-exists? "killer-app-dev")

langohr.http/user-exists?

langohr.http/user-exists? is a new function that returns true if provided user exists:

(require '[langohr.http :as hc])

(hc/user-exists? "monitoring")

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.2.4.

clj-http Upgrade

clj-http dependency has been updated to 0.7.9.

Topology Recovery Default

:automatically-recover-topology default is now true, as listed in documentation.

Contributed by Ilya Ivanov.

Deprecations

langohr.core/automatically-recover? is deprecated

Use langohr.core/automatic-recovery-enabled? instead.

Changes between Langohr 2.2.0 and 2.3.0

Recovery Predicates

langohr.core/automatic-recovery-enabled? and langohr.core/automatic-topology-recovery-enabled? are new predicate functions that return true if automatic connection and topology recovery, respectively, is enabled for the provided connection.

Topology Recovery Fails Quickly

Topology recovery now fails quickly, raising com.novemberain.langohr.recovery.TopologyRecoveryException which carries the original (cause) exception.

Previously if recovery of an entity failed, other entities were still recovered. Now topology recovery fails on the first exception, making issues more visible.

Automatic Recovery Can Be Disabled By Passing `nil`

Automatic recovery options now respect both false and nil values.

Automatic Topology Recovery Doesn't Kick In When Disabled

Automatic topology recovery no longer kicks in when it is disabled.

Changes between Langohr 2.1.0 and 2.2.0

Automatic Topology Recovery Tracks Entities Per Connection

Automatic topology recovery now tracks entities (exchanges, queues, bindings, and consumers) per connection. This makes it possible to, say, declare an exchange on one channel, delete it on another channel and not have it reappear.

Suggested by Jonathan Halterman.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.2.2.

clj-http Upgrade

clj-http dependency has been updated to 0.7.8.

Cheshire Upgrade

Cheshire dependency has been updated to 5.3.1.

Changes between Langohr 2.0.0 and 2.1.0

Full Channel State Recovery

Channel recovery now involves recovery of publisher confirms and transaction modes.

No Zombie Bindings After Recovery

Langohr now correctly removes bindings from the list of bindings to recover when a binding is removed using queue.unbind or exchange.unbind.

Changes between Langohr 1.7.0 and 2.0.0

Topology (Queues, Exchanges, Bindings, Consumers) Recovery

Connection recovery now supports entity recovery. Queues, exchanges, bindings and consumers can be recovered automatically after channel recovery. This feature is enabled by default and can be disabled by setting the :automatically-recover-topology option to false.

:requested-channel-max Connection Option

:requested-channel-max is a new option accepted by langohr.core/connect that configures how many channels this connection may have. The limit is enforced on the client side. 0 means "no limit" and is the default.

Contributed by Glophindale.

langohr.queue/empty?

langohr.queue/empty? is a new function that returns true if provided queue is empty (has 0 messages ready):

(require '[langohr.queue :as lq])

(lq/empty? ch "a.queue")
;= true

langohr.core/add-shutdown-listener

langohr.core/add-shutdown-listener is a helper function that reifies and registers a shutdown signal listener on a connection.

langohr.core/add-blocked-listener

langohr.core/add-blocked-listener is a helper function that reifies and registers a connection.blocked and connection.unblocked listener on a connection.

Changes between Langohr 1.6.0 and 1.7.0

Retries for Connection Recovery

Langohr will now make sure to handle network I/O-related exceptions during recovery and reconnect every N seconds.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.2.1.

Changes between Langohr 1.5.0 and 1.6.0

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.2.0.

Automatic Recovery Improvements

Connections will only be recovered if shutdown was not application-initiated.

Contributed by Stephen Dienst.

Support Update

Langohr now depends on ClojureWerkz Support 0.20.0.

langohr.conversion/BytePayload and langohr.conversion/to-bytes are replaced by clojurewerkz.support.bytes/ByteSource and clojurewerkz.support.bytes/to-byte-array, respectively.

Changes between Langohr 1.4.0 and 1.5.0

Automatic Recovery Improvements

Automatic recovery of channels that are created without an explicit number now works correctly.

Contributed by Joe Freeman.

clj-http Upgrade

clj-http dependency has been updated to 0.7.6.

Clojure 1.3 is No Longer Supported

Langohr requires Clojure 1.4+ as of this version.

More Convenient Publisher Confirms Support

langohr.confirm/wait-for-confirms is a new function that waits until all outstanding confirms for messages published on the given channel arrive. It optionally takes a timeout:

(langohr.confirm/wait-for-confirms ch)
;; wait up to 200 milliseconds
(langohr.confirm/wait-for-confirms ch 200)

Automatic Recovery Fix

Automatic recovery now can be enabled without causing an exception.

Changes between Langohr 1.3.0 and 1.4.0

Network Recovery Callbacks on Connections and Channels

They can be used to re-declare necessary entities using langohr.core/on-recovery:

(langohr.core/on-recovery conn (fn [conn] (comment ...)))

(langohr.core/on-recovery ch   (fn [ch] (comment ...)))

Unlike OO clients that represent queues and exchanges as objects, Langohr cannot be more aggressive about redeclaring entities during connection recovery.

Changes between Langohr 1.2.0 and 1.3.0

Re-introduce langohr.consumers/create-queueing

The function creates a QueueingConsumer instance and is very similar to langohr.consumers/create-default in purpose.

Sometimes combining a queueing consumer with langohr.consumers/deliveries-seq is the best way to express a problem.

Rename langoh.consumers/consumers-seq to langoh.consumers/deliveries-seq, make it public

langoh.consumers/deliveries-seq is a function that turns a QueueingConsumer instance into a lazy sequence of deliveries.

Use :executor During Connection Recovery

Connection recovery after network failure will now respect the :executor option.

Changes between Langohr 1.1.0 and 1.2.0

Langohr Again Uses RabbitMQ Java Client Interfaces

Langohr's implementation of connection and channel now implements RabbitMQ Java client's interfaces for connection and channel.

Changes between Langohr 1.0.0 and 1.1.0

Extended HTTP API Support

langohr.http now provides more complete coverage of the RabbitMQ HTTP API.

Contributed by Steffen Dienst.

langohr.consumers/subscribe Options In Line with Docs

The documentation says to use function handler keys ending in "-fn", but this code currently only recognizes the old form. This commit ensures that all keys that are used within langohr.consumers/subscribe can be used as a parameter.

Contributed by Steffen Dienst.

langohr.shutdown/sort-error? => langohr.shutdown/soft-error?

langohr.shutdown/soft-error? is now correctly named.

Contributed by Ralf Schmitt.

langohr.core/connect-to-first-available is Removed

langohr.core/connect-to-first-available is removed. A better failover functionality will be available in future versions.

RabbitMQ Java Client Upgrade

RabbitMQ Java client dependency has been updated to 3.1.3.

clj-http Upgrade

clj-http dependency has been updated to 0.7.4.

Cheshire Upgrade

Cheshire dependency has been updated to 5.2.0.

Changes between Langohr 1.0.0-beta13 and 1.0.0

Queueing Consumers

In its early days, Langohr has been using QueueingConsumer for langohr.queue/subscribe. It was later replaced by a DefaultConsumer implementation.

The key difference between the two is that

QueueingConsumer blocks the caller
with QueueingConsumer, deliveries are typically processed in the same thread

This implementation has pros and cons. As such, an implementation on top of QueueingConsumer is back with langohr.consumers/blocking-subscribe which is identical to langohr.consumers/subscribe in the signature but blocks the caller.

In addition, langohr.consumers/ack-unless-exception is a new convenience function that takes a delivery handler fn and will return a new function that explicitly acks deliveries unless an exception was raised by the original handler:

(require '[langohr.consumers :as lc])
(require '[langohr.basic     :as lb])

(let [f  (fn [metadata payload]
           (comment "Message delivery handler"))
      f' (lc/ack-unless-exception f)]
  (lb/consume ch q (lc/create-default :handle-delivery-fn f'))

Contributed by Ian Eure.

Shutdown Signal Functions

Several new functions in langohr.shutdown aid with shutdown signals:

langohr.shutdown/initiated-by-application?
langohr.shutdown/initiated-by-broker?
langohr.shutdown/reason-of
langohr.shutdown/channel-of
langohr.shutdown/connection-of

Clojure 1.5 By Default

Langohr now depends on org.clojure/clojure version 1.5.0. It is still compatible with Clojure 1.3 and if your project.clj depends on a different version, it will be used, but 1.5 is the default now.

We encourage all users to upgrade to 1.5, it is a drop-in replacement for the majority of projects out there.

Changes between Langohr 1.0.0-beta12 and 1.0.0-beta13

1.0.0-beta13 has BREAKING CHANGES:

langohr.consumers/subscribe Options Renamed

The options langohr.consumers/subscribe takes now have consistent naming:

:handle-consume-ok becomes :handle-consume-ok-fn
:handle-cancel becomes :handle-cancel-fn
:handle-cancel-ok becomes :handle-cancel-ok-fn
:handle-shutdown-signal-ok becomes :handle-shutdown-signal-ok-fn
:handle-recover-ok becomes :handle-recover-ok-fn
:handle-delivery-fn does not change

This makes handler argument names consistent across the board.

Previous options (:handle-cancel, etc) are still supported for backwards compatibility but will eventually be removed.

Changes between Langohr 1.0.0-beta11 and 1.0.0-beta12

Clojure-friendly Return Values

Previously functions such as langohr.queue/declare returned the underlying RabbitMQ Java client responses. In case a piece of information from the response was needed (e.g. to get the queue name that was generated by RabbitMQ), the only way to obtain it was via the Java interop.

This means developers had to learn about how the Java client works. Such responses are also needlessly unconvenient when inspecting them in the REPL.

Langohr 1.0.0-beta12 makes this much better by returning a data structure that behaves like a regular immutable Clojure map but also provides the same Java interoperability methods for backwards compatibility.

For example, langohr.queue/declare now returns a value that is a map but also provides the same .getQueue method you previously had to use.

Since the responses implement all the Clojure map interfaces, it is possible to use destructuring on them:

(require '[langohr.core  :as lhc])
(require '[langohr.queue :as lhq])

(let [conn    (lhc/connect)
      channel (lhc/create-channel conn)
      {:keys [queue] :as declare-ok} (lhq/declare channel "" :exclusive true)]
  (println "Response: " declare-ok)
  (println (format "Declared a queue named %s" queue)))

will output

Response:  {:queue amq.gen-G9bmz19UjHLBjyxhanOG3Q, :consumer-count 0, :message_count 0, :consumer_count 0, :message-count 0}
Declared a queue named amq.gen-G9bmz19UjHLBjyxhanOG3Q

langohr.confirm/add-listener Now Returns Channel

langohr.confirm/add-listener now returns the channel instead of the listener. This way it is more useful with the threading macro (->) that threads channels (a much more common use case).

langohr.exchange/unbind

langohr.exchage/unbind was missing in earlier releases and now added.

langohr.core/closed?

langohr.core/closed? is a new function that complements langohr.core/open?.

langohr.queue/declare-server-named

langohr.queue/declare-server-named is a new convenience function that declares a server-named queue and returns the name RabbitMQ generated:

(require '[langohr.core  :as lhc])
(require '[langohr.queue :as lhq])

(let [conn    (lhc/connect)
      channel (lhc/create-channel conn)
      queue   (lhq/declare-server-named channel)]
  (println (format "Declared a queue named %s" queue))

More Convenient TLS Support

Langohr will now correct the port to TLS/SSL if provided :port is 5672 (default non-TLS port) and :ssl is set to true.

Changes between Langohr 1.0.0-beta10 and 1.0.0-beta11

HTTP API Client

Langohr 1.0.0-beta11 features initial bits of RabbitMQ HTTP API client under langohr.http.

More Convenient TLS Support

Langohr will now automatically enable TLS/SSL if provided :port is 5671.

RabbitMQ Java Client 3.0.x

RabbitMQ Java Client has been upgraded to version 3.0.2.

langohr.exchange/declare-passive

langohr.exchange/declare-passive is a new function that performs passive exchange declaration (checks if an exchange exists).

An example to demonstrate:

(require '[langohr.channel  :as lch])
(require '[langohr.exchange :as le])

(let [ch (lch/open conn)]
  (le/declare-passive ch "an.exchange"))

If the exchange does exist, the function has no effect. If not, an exception (com.rabbitmq.client.ShutdownSignalException, java.io.IOException) will be thrown.

Changes between Langohr 1.0.0-beta9 and 1.0.0-beta10

langohr.basic/reject now correctly uses basic.reject

langohr.basic/reject now correctly uses basic.reject AMQP method and not basic.ack.

Contributed by @natedev.

Changes between Langohr 1.0.0-beta8 and 1.0.0-beta9

1.0.0-beta9 has BREAKING CHANGES:

Return Handlers Body Now Passed as-is

Langohr no longer instantiates a string from the message body before passing it to return listeners. The body will be passed as is, as an array of bytes.

Changes between Langohr 1.0.0-beta7 and 1.0.0-beta8

1.0.0-beta8 has BREAKING CHANGES:

langohr.basic/get Return Value Change

langohr.basic/get now returns a pair of [metadata payload] to be consistent with what delivery handler functions accept:

(require '[langohr.basic :as lhb])

(let [[metadata payload] (lhb/get channel queue)]
  (println metadata)
  (println (String. ^bytes payload)))

Changes between Langohr 1.0.0-beta6 and 1.0.0-beta7

1.0.0-beta7 has BREAKING CHANGES:

langohr.basic/consume Handler Names

The options langohr.consumers/create-default takes now have consistent naming:

:consume-ok-fn becomes :handle-consume-ok-fn
:cancel-fn becomes :handle-cancel-fn
:cancel-ok-fn becomes :handle-cancel-ok-fn
:shutdown-signal-ok-fn becomes :handle-shutdown-signal-ok-fn
:recover-ok-fn becomes :handle-recover-ok-fn
:handle-delivery-fn does not change

This makes handler argument names consistent across the board.

Changes between Langohr 1.0.0-beta5 and 1.0.0-beta6

1.0.0-beta6 has BREAKING CHANGES:

langohr.consumes/create-default Delivery Handler Signature Change

langohr.consumers/create-default's :handle-delivery-fn signature is now consistent with that of langohr.basic/subscribe:

(fn [^Channel ch metadata ^bytes payload]
  )

This makes delivery handler signatures consistent across the board.

Changes between Langohr 1.0.0-beta4 and 1.0.0-beta5

More Connection Settings

langohr.core/connect now supports several more options:

:ssl (true or false): when true, Langohr will use the default SSL protocol (SSLv3) and the default (trusting) trust manager
:ssl-context (javax.net.ssl.SSLContext): SSL context to use to create connection factory
:sasl-config (com.rabbitmq.client.SaslConfig): use if you need to use a custom SASL config
:socket-factory (javax.net.SocketFactory): use if you need to use a custom socket factory

Client Capabilities

Langohr now provides its capabilities to the broker so it's possible to tell the difference between Langohr and the RabbitMQ Java client in the RabbitMQ Management UI connection information.

Broker Capabilities Introspection

langohr.core/capabilities-of is a new function that returns broker capabilities as an immutable map, e.g.

{:exchange_exchange_bindings true
 :consumer_cancel_notify true
 :basic.nack true
 :publisher_confirms true}

Clojure 1.4 By Default

Langohr now depends on org.clojure/clojure version 1.4.0. It is still compatible with Clojure 1.3 and if your project.clj depends on 1.3, it will be used, but 1.4 is the default now.

We encourage all users to upgrade to 1.4, it is a drop-in replacement for the majority of projects out there.

Changes between Langohr 1.0.0-beta3 and 1.0.0-beta4

Payload is Now Longer Assumed to Be a String

langohr.basic/publish no longer assumes the payload is always a string. It can be anything the langohr.conversion/BytePayload protocol is implemented for, by default byte arrays and strings.

queue.declare :exclusive Default Value Change

langohr.queue/declare now uses default value for the :exclusive parameter as false. The reason for this is that exclusive queues are deleted when connection that created them is closed. This caused confusion w.r.t. non-auto-deleted queues being deleted in such cases.

Changes between Langohr 1.0.0-beta2 and 1.0.0-beta3

URI parsing

langohr.core/settings-from is a new public API function that parses AMQP and AMQPS connection URIs and returns an immutable map of individual arguments. URI parsing is now delegated to the Java client for consistency.

RabbitMQ Java Client 2.8.6

RabbitMQ Java Client has been upgraded to version 2.8.6.

Changes between Langohr 1.0.0-beta1 and 1.0.0-beta2

Breaking change: message handler signature has changed

Previously message handlers registered via langohr.consumers/subscribe had the following signature:

(fn [^QueueingConsumer$Delivery delivery ^AMQP$BasicProperties properties payload] ...)

starting with beta2, it has changed to be more Clojure friendly

(fn [^Channel ch metadata payload] ...)

All message metadata (both envelope and message properties) are now passed in as a single Clojure map that you can use destructuring on:

(fn [^Channel ch {:keys [type content-type message-id correlation-id] :as metadata} payload] ...)

In addition, in explicit acknowledgement mode, ack-ing and nack-ing messages got easier because consumer channel is now passed in.

It is important to remember that sharing channels between threads that publish messages is dangerous and should be avoided. Ack-ing, nack-ing and consuming messages with shared channels is usually acceptable.

RabbitMQ Java Client 2.8.x

RabbitMQ Java Client which Langohr is based on has been upgraded to version 2.8.1.

Leiningen 2

Langohr now uses Leiningen 2.

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