Clojure API for a more dynamic Google Cloud Dataflow and (not really battle tested) any other Apache Beam backend.
You can also see ports of the official Dataflow examples in the
datasplash.examples
namespace.
Here is the classic word count:
(ns datasplash.examples
(:require [clojure.string :as str]
[clojure.tools.logging :as log]
[datasplash
[api :as ds]
[bq :as bq]
[datastore :as dts]
[pubsub :as ps]
[options :as options :refer [defoptions]]]
[clojure.edn :as edn])
(:import [java.util UUID]
[com.google.datastore.v1 Query PropertyFilter$Operator]
[com.google.datastore.v1.client DatastoreHelper]
[org.apache.beam.sdk.options PipelineOptionsFactory])
(:gen-class))
(defn tokenize
[l]
(remove empty? (.split (str/trim l) "[^a-zA-Z']+")))
(defn count-words
[p]
(ds/->> :count-words p
(ds/mapcat tokenize {:name :tokenize})
(ds/frequencies)))
(defn format-count
[[k v]]
(format "%s: %d" k v))
(defoptions WordCountOptions
{:input {:default "gs://dataflow-samples/shakespeare/kinglear.txt"
:type String}
:output {:default "kinglear-freqs.txt"
:type String}
:numShards {:default 0
:type Long}})
(defn -main
[& str-args]
(let [p (ds/make-pipeline WordCountOptions str-args)
{:keys [input output numShards]} (ds/get-pipeline-options p)]
(->> p
(ds/read-text-file input {:name "King-Lear"})
(count-words)
(ds/map format-count {:name :format-count})
(ds/write-text-file output {:num-shards numShards})
(ds/run-pipeline))))
Run it from the repl with:
(in-ns 'datasplash.examples)
(compile 'datasplash.examples)
(-main "--input=in.txt" "--output=out.txt")
Note that you will need to run (compile 'datasplash.examples)
every time you
make a change.
Run an example from the examples namespace locally with:
lein run example-name --input=in.txt --output=out.txt
Run in on Google Cloud (if you have done a gcloud init
on this machine):
lein run example-name --input=gs://dataflow-samples/shakespeare/kinglear.txt --output=gs://my-project-tmp/results.txt --runner=DataflowPipeline --project=my-project --stagingLocation=gs://my-project-staging
require
.ParDo
objects (you shouldn't), wrap
all your code in the safe-exec
macro to avoid issues with unbound vars. Any
good idea about finding a better way to do this would be greatly appreciated!UserCodeException
as seen in the cloud UI are mangled and
missing the relevant part of the Clojure source code, this is due to a bug
with the way the sdk mangles stacktraces in Clojure. In this case look for
ClojureRuntimeException in the logs to find the original unaltered
stacktrace.proxy
results are not Serializable
anymore,
so you cannot use anywhere in your pipeline Clojure code that uses proxy. Use
Java shim for these objects instead.java.lang.ClassNotFoundException: Options
you
probably forgot to compile your namespace.java.io.IOException: No such file or directory
when invoking
compile
, make sure there is a directory in your project root that matches
the value of *compile-path*
(default classes
).Copyright © 2015-2019 Oscaro.com
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.
Can you improve this documentation? These fine people already did:
Nils Grunwald, Baptiste Fontaine, Nils, Michael Laroche, Amar Mehta, Jason & Eric FodeEdit on GitHub
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