The ClojureWerkz Blog

News and updates about ClojureWerkz projects

Langohr 3.1.0 Is Released

TL;DR

Langohr is a small Clojure RabbitMQ client.

3.1.0 upgrades dependencies and includes one bug fix in Langohr itself.

Changes between Langohr 3.0.x 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.

Change Log

Langohr change log is available on GitHub.

Langohr is a ClojureWerkz Project

Langohr is part of the group of libraries known as ClojureWerkz, together with

  • Elastisch, a minimalistic well documented Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client built around CQL 3.0
  • Monger, a Clojure MongoDB client for a more civilized age
  • Neocons, a client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Langohr, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About The Author

Michael on behalf of the ClojureWerkz Team

Monger 2.1.0 Is Released

TL;DR

Monger is an idiomatic Clojure MongoDB driver for a more civilized age. It has batteries included, offers powerful expressive query DSL, strives to support every MongoDB 2.0+ feature and has sane defaults. It also has solid documentation.

2.1.0 is a compatibility release. Next feature release of Monger will be 3.0 and will use version 3.0 of the MongoDB Java driver.

Changes between 2.0.0 and 2.1.0

Clojure 1.7 Compatibility

Improved Clojure 1.7 (development milestone) releases.

MongoDB Java Driver Update

MongoDB Java driver dependency has been updated to 2.13.x.

$each Operator

The $each operator now can be used via monger.operators.

Contributed by Juha Jokimäki.

Change Log

Monger change log is available on GitHub.

Monger is a ClojureWerkz Project

Monger is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Cassaforte, a Clojure Cassandra client built around CQL
  • Elastisch, a minimalistic Clojure client for ElasticSearch
  • Welle, a Riak client with batteries included
  • Neocons, a client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Monger, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About the Author

@michaelklishin on behalf of the ClojureWerkz Team

Elastisch 2.2.0-beta1 Is Released

TL;DR

Elastisch is a battle tested, small but feature rich and well documented Clojure client for ElasticSearch. It supports virtually every Elastic Search feature and has solid documentation.

2.2.0-beta1 is a preview release of Elastisch 2.2 which introduces a few minor improvements.

Changes between Elastisch 2.1.x and 2.2.0-beta1

Add support for Nested Aggregations in the Native Client

Native client now supports nesting in the following aggregations

  • histogram
  • date_histogram
  • range
  • date_range
  • terms

Contributed by Mitchel Kuijpers.

ElasticSearch Java Client Upgrade

Elastisch now depends on ElasticSearch Java client version 1.4.x.

clj-http Update

clj-http dependency has been upgraded to version 1.0.1.

Cheshire Update

Cheshire dependency has been upgraded to version 5.4.0.

Full Change Log

Elastisch change log is available on GitHub.

Thank You, Contributors

Kudos to Michael Nussbaum and Jeffrey Erikson for contributing to this release.

Elastisch is a ClojureWerkz Project

Elastisch is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Cassaforte, a Clojure Cassandra client
  • Monger, a Clojure MongoDB client for a more civilized age
  • Titanium, a Clojure graph library
  • Neocons, a client for the Neo4J REST API
  • Welle, a Riak client with batteries included
  • Quartzite, a powerful scheduling library

and several others. If you like Elastisch, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About the Author

Michael on behalf of the ClojureWerkz Team

Pantomime 2.4.0 Is Released

TL;DR

Pantomime is a tiny Clojure library for working with MIME types and file metadata.

Changes between Pantomime 2.3.0 and 2.4.0

Apache Tika 1.7

Apache Tika dependency has been upgraded to version 1.7.

Change Log

Pantomime change log is available on GitHub.

Pantomime is a ClojureWerkz Project

Pantomime is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Elastisch, a minimalistic Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client built around CQL
  • Monger, a Clojure MongoDB client for a more civilized age
  • Welle, a Riak client with batteries included
  • Neocons, a client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Pantomime, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

Michael on behalf of the ClojureWerkz Team

EEP 1.0.0-beta1 Is Released

EEP (Embeded Event Processing) is a Clojure stream processing library.

1.0.0-beta1 is a development milestone that introduces a breaking public API change and adapts to Meltdown 1.1.x releases.

Changes between 1.0.0-alpha5 and 1.0.0-beta1

beta1 has breaking public API changes.

Emitter Creation API Change

clojurewerkz.eep.emitter/create no longer uses pseudo-kwargs. So, instead of

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(require '[clojurewerkz.eep.emitter :as eem])

(let [me (eem/create :dispatcher-type rtype :env env)]
  )

use the function like so

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(require '[clojurewerkz.eep.emitter :as eem])

(let [me (eem/create {:dispatcher-type rtype :env env})]
  )

Clojure 1.6

EEP 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.

Change log

EEP change log is available on GitHub.

EEP is a ClojureWerkz Project

EEP is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Elastisch, a small feature complete Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client
  • Monger, a Clojure MongoDB client for a more civilized age
  • Titanium, a Clojure graph library
  • Meltdown, a fast message passing library built on top of Reactor
  • Welle, a Riak client with batteries included
  • Quartzite, a powerful scheduling library

and several others. If you like Elastisch, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

Michael on behalf of the ClojureWerkz Team

Serialism 1.3.0 Is Released

TL;DR

Serialism a tiny Clojure library that serializes and deserializes values into popular formats based on provided content type.

Changes Between 1.2.0 and 1.3.0

Double License

The library is now double-licensed under Apache Public License 2.0 and Eclipse Public License 1.0.

Cheshire 5.4

The library now depends on Cheshire 5.4.

Full Change Log

Serialism change log is available on GitHub.

Serialism is a ClojureWerkz Project

Serialism is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Elastisch, a minimalistic Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client built around CQL
  • Monger, a Clojure MongoDB client for a more civilized age
  • Neocons, a client for the Neo4J REST API
  • Welle, a Riak client with batteries included
  • Quartzite, a powerful scheduling library

and several others. If you like Serialism, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About The Author

Michael on behalf of the ClojureWerkz Team

Quartzite 2.0 Is Released

Quartzite is a Clojure DSL on top of the Quartz scheduler.

2.0.0 is a major release that contains breaking public API changes.

Changes Between Quartzite 1.3.0 and 2.0.0

Scheduler as Explicit Arguments

Following our commitment to make our projects rely less on dynamic vars we have changed clojurewerkz.quartzite.scheduler function to take an explicit scheduler argument.

So, in 1.3 releases, you would do:

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(require '[clojurewerkz.quartzite.scheduler :as qs])

(qs/initialize)
(qs/start)
(qs/schedule job-detail trigger)
(qs/shutdown)

and in 2.0 release, the same code would look like so:

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(require '[clojurewerkz.quartzite.scheduler :as qs])

(let [s (-> (qs/initialize) qs/start)]
  (qs/schedule s job-detail trigger)
  (qs/shutdown s))

quartzite.date-time is Gone

clojurewerkz.quartzite.date-time was removed as all of the functions in that namespace have been contributed to clj-time a while ago, and some provide more correct or extensible functionality.

Simply use clj-time counterparts when upgrading.

Clojure 1.4 and 1.5 are No Longer Supported

The library no longer supports Clojure 1.4 and 1.5 as of this version.

Change Log

Quartzite change log is available on GitHub.

Quartzite is a ClojureWerkz Project

Quartzite is part of the group of libraries known as ClojureWerkz, together with

  • Elastisch, a minimalistic Clojure client for ElasticSearch
  • Monger, a Clojure MongoDB driver for a more civilized age
  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Welle, a Riak client with batteries included
  • Neocons, a client for the Neo4J REST API

and several others. If you like Quartzite, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

@michaelklishin on behalf of the ClojureWerkz Team

Langohr 3.0.1 Is Released

TL;DR

Langohr is a small Clojure RabbitMQ client.

3.0.1 is a bug fix release.

Changes between Langohr 3.0.0 and 3.0.1

langohr.consumers/blocking-subscribe No Longer Fails

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

GH issue: #65.

Change Log

Langohr change log is available on GitHub.

Langohr is a ClojureWerkz Project

Langohr is part of the group of libraries known as ClojureWerkz, together with

  • Elastisch, a minimalistic well documented Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client built around CQL 3.0
  • Monger, a Clojure MongoDB client for a more civilized age
  • Neocons, a client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Langohr, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About The Author

Michael on behalf of the ClojureWerkz Team

Langohr 3.0.0 Is Released

TL;DR

Langohr is a Clojure RabbitMQ client that embraces AMQP 0.9.1 Model.

3.0.0 is a major release that introduces breaking API changes, JDK 8 compatibility, minor new features and major internal revamp.

Options as Maps

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

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;; 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:

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(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.

Change Log

Langohr change log is available on GitHub.

Langohr is a ClojureWerkz Project

Langohr is part of the group of libraries known as ClojureWerkz, together with

  • Elastisch, a minimalistic well documented Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client built around CQL 3.0
  • Monger, a Clojure MongoDB client for a more civilized age
  • Neocons, a client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Langohr, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About the Author

Michael on behalf of the ClojureWerkz Team

Cassaforte 2.0.0 Is Released

TL;DR

Cassaforte is a Clojure client for Apache Cassandra and DataStax Enterprise. It is built around CQL 3 and focuses on ease of use. You will likely find that using Cassandra from Clojure has never been so easy.

2.0.0 is a major release that introduces breaking API changes, new features and compatibility with Cassandra 2.1.

Changes between 1.3.x and 2.0.0

Cassaforte 2.0 has breaking API changes in most namespaces.

Client (Session) is Explicit Argument

All Cassaforte public API functions that issue requests to Cassandra now require a client (session) to be passed as an explicit argument:

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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]
            [clojurewerkz.cassaforte.cql    :as cql]))

(let [conn (cc/connect ["127.0.0.1"])]
  (cql/use-keyspace conn "cassaforte_keyspace"))
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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]
            [clojurewerkz.cassaforte.cql    :as cql]
            [clojurewerkz.cassaforte.query :refer :all]))

(let [conn (cc/connect ["127.0.0.1"])]
  (cql/create-table conn "user_posts"
                (column-definitions {:username :varchar
                                     :post_id  :varchar
                                     :body     :text
                                     :primary-key [:username :post_id]})))
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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]
            [clojurewerkz.cassaforte.cql    :as cql]))

(let [conn (cc/connect ["127.0.0.1"])]
  (cql/insert conn "users" {:name "Alex" :age (int 19)}))

Hayt 2.0

Hayt dependency has been upgraded to 2.0 (GA).

Query DSL Taken From Hayt 2.0

Cassaforte no longer tries to support query condition DSLs for both Hayt 1.x and Hayt 2.0. Hayt 2.0 is the only supported flavour now and is the future.

Some examples of the changes:

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;; before
(where :name "Alex")

;; after
(where [[= :name "Alex"]])
(where {:name "Alex"})


;; before
(where :name "Alex" :city "Munich")

;; after
(where [[= :name "Alex"]
        [= :city "Munich"]])
(where {:name "Alex" :city "Munich"})


;; before
(where :name "Alex" :age [> 25])

;; after
(where [[= :name "Alex"]
        [> :age  25]])

;; before
(where :name "Alex" :city [:in ["Munich" "Frankfurt"]])

;; after
(where [[= :name "Alex"]
        [:in :city ["Munich" "Frankfurt"]]])

As it’s easy to see, the new condition style closer resembles Clojure itself and thus was a reasonable decision on behalf of Hayt developers.

Policy Namespace

Policy-related functions from clojurewerkz.cassaforte.client were extracted into clojurewerkz.cassaforte.policies:

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(require '[clojurewerkz.cassaforte.policies :as cp])

(cp/exponential-reconnection-policy 100 1000)
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(require '[clojurewerkz.cassaforte.policies :as cp])

(let [p (cp/round-robin-policy)]
  (cp/token-aware-policy p))

DataStax Java Driver Update

DataStax Java driver has been updated to 2.1.x.

Cassandra 2.1 Compatibility

Cassaforte 2.0 is compatible with Cassandra 2.1.

Cassandra Sessions Compatible with with-open

Session#shutdown was renamed to Session#close in cassandra-driver-core. Cassaforte needs to be adapted to that.

Contributed by Jarkko Mönkkönen.

TLS and Kerberos Support

Cassaforte now supports TLS connections and Kerberos authentication via DataStax CQL extensions.

The :ssl connection option now can be a map with two keys:

  • :keystore-path
  • :keystore-password

which provide a path and password to a JDK KeyStore on disk, created with keytool.

Optionally, an instance of SSLOptions can be provided via the :ssl-options connection option.

Contributed by Max Barnash.

GH issue: #60.

Support for overriding default SSL cipher suites

Providing a :cipher-suites key in the :ssl connection option allows to specify cipher suites that are enabled when connecting to a cluster with SSL. The value of this key is a Seq of Strings (e.g. a vector) where each item specifies a cipher suite:

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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]))

(cc/build-cluster {:ssl {:keystore-path "path/to/keystore"
                         :keystore-password "password"}})]
                         :cipher-suites ["TLS_RSA_WITH_AES_128_CBC_SHA"]}}

The :cipher-suites key is optional and may be omitted, in which case Datastax Java driver’s default cipher suites (com.datastax.driver.core.SSLOptions/DEFAULT_SSL_CIPHER_SUITES) are enabled.

This can be used to work around the need to install Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files required by the default set of cipher suites. TLS_RSA_WITH_AES_128_CBC_SHA is a suite in the default set that works with the standard JCE. E.g. by specifying just that one, as in the code example, the standard JCE is enough.

Contributed by Juhani Hietikko.

GH issue: #61.

Cassandra Native Protocol v2 as Default

To preserve Cassandra 2.0 compatibility yet continue using the most recent Cassandra Java driver Cassaforte now uses native protocol v2 by default. v3 can be opted into using the :protocol-version connection option (with value of 3).

Double Licensed Under APL 2.0 and EPL 1.0

The project is now double-licensed under the Eclipse Public License 1.0 and Apache Public License 2.0. The codebase now includes APL 2.0 headers. License files for both APL 2.0 and EPL 1.0 are included in the distribution.

Fetch Size Support

(Internal to the client) automatic paging of result set rows now can be configured or disabled altogether, e.g. when running into problems similar to CASSANDRA-6722.

clojurewerkz.cassaforte.client/with-fetch-size is a macro that does that:

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(require '[clojurewerkz.cassaforte.client :as cc])

;; alter page size
(cc/with-fetch-size 8192
  (comment "SELECT queries go here"))

;; disable internal client paging
(cc/with-fetch-size Integer/MAX_VALUE
  (comment "SELECT queries go here"))

Default fetch size is unaltered (Cassaforte relies on the Java driver default). This setting only makes sense for a certain subset of SELECT queries.

Clojure 1.4 and 1.5 Support Dropped

Cassaforte now requires Clojure 1.6.0.

Collections Converted to Clojure Data Structures

Cassandra maps, sets and lists are now automatically converted to their immutable Clojure counterparts.

Atomic Batches Support

Atomic batches are now easier to use with Cassaforte:

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(require '[clojurewerkz.cassaforte.client :as client])
(require '[clojurewerkz.cassaforte.cql :as cql :refer :all])
(require '[clojurewerkz.cassaforte.query :refer :all])
(require '[qbits.hayt.dsl.statement :as hs])

(let [s (client/connect ["127.0.0.1"])]
  (cql/atomic-batch s (queries
                         (hs/insert :users (values {:name "Alex" :city "Munich" :age (int 19)}))
                         (hs/insert :users (values {:name "Fritz" :city "Hamburg" :age (int 28)})))))

clojurewerkz.cassandra.cql/iterate-table Now Terminates

clojurewerkz.cassandra.cql/iterate-table no longer produces an infinite sequence.

Keyspace as Option

It is now possible to choose keyspace via an option:

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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]))

(let [conn (cc/connect {:hosts ["127.0.0.1"] :keyspace "a-keyspace"})]
  )

Contributed by Max Barnash (DataStax).

URI Connections

It is now possible to connect to a node and switch to a namespace using a URI string:

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(ns cassaforte.docs
  (:require [clojurewerkz.cassaforte.client :as cc]))

;; connects to node 127.0.0.1:9042 and uses "new_cql_keyspace" as keyspace
(cc/connect-with-uri "cql://127.0.0.1:9042/new_cql_keyspace")

Compression Option

:compression is a new option that can be used when connecting:

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(require '[clojurewerkz.cassaforte.client :as client])

(let [s (client/connect ["127.0.0.1"] "my-keyspace" {:compression :snappy})]
  )

Valid compression values are:

  • :snappy
  • :lz4
  • :none (or nil)

Contirbuted by Max Barnash (DataStax).

Fixes Race Condition in Async Operations

Async database operations no longer suffer from a race condition between issueing them and definiting callbacks on the returned future value.

Contributed by Kirill Chernyshov.

Correct Deserialisation of Empty Strings

Empty string values are now correctly deserialised (previously they were returned as nil).

GH issue: #91.

Prepared Statement Cache Removed

Prepared statement cache was affecting client correctness in some cases and was removed.

Clojure 1.7.0-alpha2+ Compatibility

Cassaforte is now compatible with Clojure 1.7.0-alpha2 and later versions.

News and Updates

New releases and updates are announced on Twitter. Cassaforte also has a mailing list, feel free to ask questions and report issues there.

Cassaforte is a ClojureWerkz Project

Cassaforte is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Monger, a Clojure MongoDB client for a more civilized age
  • Elastisch, a minimalistic Clojure client for ElasticSearch
  • EEP, a Clojure library for stream (event) processing
  • Neocons, a Clojure client for the Neo4J REST API
  • Quartzite, a powerful scheduling library

and several others. If you like Cassaforte, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

About the Author

Michael on behalf of the ClojureWerkz Team.