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Spark Notebook

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24 April 2015


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Spark Notebook

Description

The main intent of this tool is to create reproducible analysis using Scala, Apache Spark and more.

This is achieved through an interactive web-based editor that can combine Scala code, SQL queries, Markup or even JavaScript in a collaborative manner.

The usage of Spark comes out of the box, and is simply enabled by the implicit variable named sparkContext.

Discussions

C’mon on gitter!

Mailing list

There are two different mailing lists, each aiming to specific discussions:

Spark Notebook Dev

Then spark-notebook-dev mailing list for all threads regarding implementation, architecture, features and what not related to fix or enhance the project.

Email: spark-notebook-dev@googlegroups.com.

Spark Notebook User

The spark-notebook-user is for almost everything else than dev, which are questions, bugs, complains, or hopefully some kindness :-D.

Email: spark-notebook-user@googlegroups.com.

Launch

Using a release

Long story short, there are several ways to start the spark notebook quickly (even from scratch):

However, there are several flavors for these distributions that depends on the Spark version and Hadoop version you are using.

Requirements

  • Make sure you’re running at least Java 7 (sudo apt-get install openjdk-7-jdk).

Preferred/Simplest way

Head to http://spark-notebook.io.

You’ll be presented a form to get the distribution you want. If not available, it’ll gracefully build it for you and notify you want it’ll be ready

IMPORTANT: then you can check the related section for instructions on how to use it (although it’s very easy).

Hard ways

ZIP/TGZ

The zip/tgz distributions are publicly available in the bucket: s3://spark-notebook.

Here is an example for zip (replace all zip by tgz for the tarbal version):

wget https://s3.eu-central-1.amazonaws.com/spark-notebook/zip/spark-notebook-0.4.0-scala-2.10.4-spark-1.3.0-hadoop-1.0.4.zip
unzip spark-notebook-0.2.0-spark-1.2.0-hadoop-1.0.4.zip
cd spark-notebook-0.2.0-spark-1.2.0-hadoop-1.0.4
./bin/spark-notebook

Docker

If you’re a Docker user, the following procedure will be even simpler!

Checkout the needed version here.

docker pull andypetrella/spark-notebook:0.4.0-scala-2.10.4-spark-1.2.1-hadoop-2.4.0
docker run -p 9000:9000 andypetrella/spark-notebook:0.4.0-scala-2.10.4-spark-1.2.1-hadoop-2.4.0

boot2docker (Mac OS X)

On Mac OS X, you need something like boot2docker to use docker. However, port forwarding needs an extra command necessary for it to work (cf this and this SO questions).

VBoxManage modifyvm "boot2docker-vm" --natpf1 "tcp-port9000,tcp,,9000,,9000"

DEB

Using debian packages is one of the standard, hence the spark notebook is also available in this form (from v0.4.0):

wget https://s3.eu-central-1.amazonaws.com/spark-notebook/deb/spark-notebook_0.4.0-scala-2.10.4-spark-1.3.0-hadoop-1.0.4_all.deb
sudo dpkg -i spark-notebook_0.4.0-scala-2.10.4-spark-1.3.0-hadoop-1.0.4_all.deb
sudo spark-notebook

Checkout the needed version here.

From the sources

The spark notebook requires a Java(TM) environment (aka JVM) as runtime and SBT to build it.

Of course, you will also need a working GIT installation to download the code and build it.

Procedure

Download the code

git clone https://github.com/andypetrella/spark-notebook.git
cd spark-notebook

Launch the server

Enter the sbt console by running sbt within the spark-notebook folder:

[info] Loading global plugins from /home/noootsab/.sbt/0.13/plugins
[info] Loading project definition from /home/Sources/noootsab/spark-notebook/project
[info] Set current project to spark-notebook (in build file:/home/Sources/noootsab/spark-notebook/)
       _
 _ __ | | __ _ _  _
| '_ \| |/ _' | || |
|  __/|_|\____|\__ /
|_|            |__/

play 2.2.6 built with Scala 2.10.3 (running Java 1.7.0_72), http://www.playframework.com

> Type "help play" or "license" for more information.
> Type "exit" or use Ctrl+D to leave this console.

[spark-notebook] $

Change relevant versions

When using Spark we generally have to take a lot of care with the Spark version itself but also the Hadoop version. There is another dependency which is tricky to update, the jets3t one.

To update that, you can pass those version as properties, here is an example with the current default ones:

sbt -D"spark.version"="1.2.1" -D"hadoop.version"="1.0.4" -D"jets3t.version"="0.7.1"

Create your distribution

[spark-notebook] $ dist

In order to develop on the Spark Notebook, you’ll have to use the run command instead.

Use

When the server has been started, you can head to the page http://localhost:9000 and you’ll see something similar to: Notebook list

From there you can either:

  • create a new notebook or
  • launch an existing notebook

In both case, the scala-notebook will open a new tab with your notebook in it, loaded as a web page.

Note: a notebook is a JSON file containing the layout and analysis blocks, and it’s located within the project folder (with the snb extension). Hence, they can be shared and we can track their history in an SVM like GIT.

Features

Configure Spark

Since this project aims directly the usage of Spark, a SparkContext is added to the environment and can directly be used without additional effort.

Example using Spark

By default, Spark will start with a regular/basic configuration. There are different ways to customize the embedded Spark to your needs.

Preconfigure Spark

The cleanest way to configure Spark is actually to use the preconfiguration feature available in the clusters tab.

The basic idea is to configure a template that will act as a factory for notebooks: Clusters

Then you’ll have to fill some informations as Json, where you’ll have to give a name and specify a profile. But specially:

Set local repository

When adding dependencies, it can be interesting to preconfigure a repository where some dependencies have been already fetched.

This will save the dependency manager to download the internet.

    "customLocalRepo" : "/<home>/.m2/repository",

Add remote repositories

Some dependencies might not be available from usual repositories.

While the context :remote-repo is available from the notebook, we can also add them right in the preconfiguration:

    "customRepos"     : [
      "s3-repo % default % s3://<bucket-name>/<path-to-repo> % (\"$AWS_ACCESS_KEY_ID\", \"$AWS_SECRET_ACCESS_KEY\")",
      "local % default % file://<home>/.m2/repository"
    ],

Import (download) dependencies

Adding dependencies in the classpath and in the spark context can be done, this way (see also :dp).

    "customDeps"      : "med-at-scale        %  ga4gh-model-java % 0.1.0-SNAPSHOT\norg.apache.avro     %  avro-ipc         % 1.7.6\n- org.mortbay.jetty % org.eclipse.jetty % _",

Default import statements

Some package, classes, types, functions and so forth could be automatically imported, by using:

    "customImports"   : "import scala.util.Random\n",

Spark Conf

Apache Spark needs some configuration to access clusters, tune the memory and many others.

For this configuration to be shareable, and you don’t want to use the reset functions, you can add:

    "customSparkConf" : {
      "spark.app.name": "Notebook",
      "spark.master": "local[8]",
      "spark.executor.memory": "1G"
    }

Example

{
  "name": "My cluster conf",
  "profile": "Local",
  "template": {
    "customLocalRepo" : "/<home>/.m2/repository",
    "customRepos"     : [
      "s3-repo % default % s3://<bucket-name>/<path-to-repo> % (\"$AWS_ACCESS_KEY_ID\", \"$AWS_SECRET_ACCESS_KEY\")",
      "local % default % file://<home>/.m2/repository"
    ],
    "customDeps"      : "med-at-scale        %  ga4gh-model-java % 0.1.0-SNAPSHOT\norg.apache.avro     %  avro-ipc         % 1.7.6\n- org.mortbay.jetty % org.eclipse.jetty % _",
    "customImports"   : "import scala.util.Random\n",
    "customSparkConf" : {
      "spark.app.name": "Notebook",
      "spark.master": "local[8]",
      "spark.executor.memory": "1G"
    }
  }
}

Clusters

YARN

  • Example YARN Cluster
  "Example YARN" : {
    "name" : "Example YARN-Client",
    "profile" : "yarn-client",
    "status" : "stopped",
    "template" : {
      "customLocalRepo" : "",
      "customRepos" : [ ],
      "customDeps" : [ ],
      "customImports" : [ ],
      "customSparkConf" : {
        "spark.app.name" : "Notebook",
        "spark.master" : "yarn-client",
        "spark.executor.memory" : "1G",
        "spark.yarn.jar" : "hdfs:///user/spark/spark-assembly.jar"
      }
    }
  }
  • Example YARN Profile
  "yarn" : {
      "id" : "yarn-client",
      "name" : "YARN-Client",
      "template" : {
        "customLocalRepo" : null,
        "customRepos" : null,
        "customDeps" : null,
        "customImports" : null,
        "customSparkConf" : {
          "spark.app.name" : "Notebook",
          "spark.master" : "yarn-client",
          "spark.executor.memory" : "1G",
          "spark.yarn.jar" : "hdfs:///user/spark/spark-assembly.jar"
        }
      }
   }

To using YARN cluster,

  1. Put the spark-assembly-*.jar to the HDFS
# sudo -u hdfs hdfs dfs -mkdir -p /user/spark
# sudo -u hdfs hdfs dfs -put /usr/lib/spark/lib/spark-assembly.jar /user/spark/spark-assembly.jar
  1. Point the location of spark-assembly.jar with spark.yarn.jar property.
  2. Add Hadoop Conf dir such as /etc/hadoop/conf to the classpath in the executable script bin/spark-notebook:
declare -r script_conf_file="/etc/default/spark-notebook"

declare -r app_classpath="/etc/hadoop/conf:$lib_dir/...

addJava "-Duser.dir=$(cd "${app_home}/.."; pwd -P)"
  1. Start spark-notebook, then create notebook from example yarn cluster. After a while, spark should be initialized and sparkContext will be ready to use.

Create a preconfigured notebook

Now you can use the configuration, by clicking create Clusters

You’ll have the hand on the configuration (fine tuning) before creating the notebook: Clusters

Update preconfigurations in metadata

Actually, the configuration are stored in the metadata of the notebooks.

To change them, simply go to edit > Edit Notebook Metadata and you’ll have: Clusters

Use the form

In order to adapt the configuration of the SparkContext, one can add the widget notebook.front.widgets.Spark. This widget takes the current context as only argument and will produce an HTML form that will allow manual and friendly changes to be applied.

So first, adding the widget in a cell,

import notebook.front.widgets.Spark
new Spark(sparkContext)

Run the cell and you’ll get, Using SQL

It has two parts:

  • the first one is showing an input for each current properties
  • the second will add new entries in the configuration based on the provided name

Submit the first part and the SparkContext will restart in the background (you can check the Spark UI to check if you like).

The reset function

The function reset is available in all notebooks: This function takes several parameters, but the most important one is lastChanges which is itself a function that can adapt the SparkConf. This way, we can change the master, the executor memory and a cassandra sink or whatever before restarting it. For more Spark configuration options see: Spark Configuration

In this example we reset SparkContext and add configuration options to use the [cassandra-connector]:

import org.apache.spark.{Logging, SparkConf}
val cassandraHost:String = "localhost"
reset(lastChanges= _.set("spark.cassandra.connection.host", cassandraHost))

This makes Cassandra connector avaible in the Spark Context. Then you can use it, like so:

import com.datastax.spark.connector._
sparkContext.cassandraTable("test_keyspace", "test_column_family")

Keep an eye on your tasks

Accessing the Spark UI is not always allowed or easy, hence a simple widget is available for us to keep a little eye on the stages running on the Spark cluster.

Luckily, it’s fairly easy, just add this to the notebook:

import org.apache.spark.ui.notebook.front.widgets.SparkInfo
import scala.concurrent.duration._
new SparkInfo(sparkContext, checkInterval=1 second, execNumber=Some(100))

This call will show and update a feedback panel tracking some basic (atm) metrics, in this configuration there will be one check per second, but will check only 100 times.

This can be tuned at will, for instance for an infinte checking, one can pass the None value to the argument execNumber.

Counting the words of a wikipedia dump will result in Showing progress

Using (Spark)SQL

Spark comes with this handy and cool feature that we can write some SQL queries rather than boilerplating with Scala or whatever code, with the clear advantage that the resulting DAG is optimized.

The spark-notebook offers SparkSQL support. To access it, we first we need to register an RDD as a table:

dataRDD.registerTempTable("data")

Now, we can play with SQL in two different ways, the static and the dynamic ones.

Static SQL

Then we can play with this data table like so:

:sql select col1 from data where col2 == 'thingy'

This will give access to the result via the resXYZ variable.

This is already helpful, but the resXYZ nummering can change and is not friendly, so we can also give a name to the result:

:sql[col1Var] select col1 from data where col2 == 'thingy'

Now, we can use the variable col1Var wrapping a SchemaRDD.

This variable is reactive meaning that it react to the change of the SQL result. Hence in order to deal with the result, you can access its react function which takes two arguments:

  • a function to apply on the underlying SchemaRDD to compute a result
  • a widget that will take the result of the function applied to the SchemaRDD and use it to update its rendering

The power of this reactivity is increased when we use SQL with dynamic parts.

Dynamic SQL

A dynamic SQL is looking like a static SQL but where specific tokens are used. Such tokens are taking the form: {type: variableName}.

When executing the command, the notebook will produce a form by generating on input for each dynamic part. See the show case below.

An example of such dynamic SQL is

:sql[selectKids] SELECT name FROM people WHERE name = "{String: name}" and age >= {Int: age}

Which will create a form with to inputs, one text and on number.

When changing the value in the inputs, the SQL is compiled on the server and the result is printed on the notebook (Success, Failure, Bad Plan, etc.).

Again, the result is completely reactive, hence using the react function is mandatory to use the underlying SchemaRDD (when it becomes valid!).

Show case

This is how it looks like in the notebook:

Using SQL

Shell scripts :sh

There is a way to easily use (rudimentary) shell scripts via the :sh context.

:sh ls -la ~/data

Interacting with JavaScript

Showing numbers can be good but great analysis reports should include relevant charts, for that we need JavaScript to manipulate the notebook’s DOM.

For that purpose, a notebook can use the Playground abstraction. It allows us to create data in Scala and use it in predefined JavaScript functions (located under assets/javascripts/notebook) or even JavaScript snippets (that is, written straight in the notebook as a Scala String to be sent to the JavaScript interpreter).

The JavaScript function will be called with these parameters:

  • the data observable: a JS function can register its new data via subscribe.
  • the dom element: so that it can update it with custom behavior
  • an extra object: any additional data, configuration or whatever that comes from the Scala side

Here is how this can be used, with a predefined consoleDir JS function (see here):

Simple Playground

Another example using the same predefined function and example to react on the new incoming data (more in further section). The new stuff here is the use of Codec to convert a Scala object into the JSON format used in JS:

Playground with custom data

Plotting with D3

Plotting with D3.js is rather common now, however it’s not always simple, hence there is a Scala wrapper that brings the bootstrap of D3 in the mix.

These wrappers are D3.svg and D3.linePlot, and they are just a proof of concept for now. The idea is to bring Scala data to D3.js then create Coffeescript to interact with them.

For instance, linePlot is used like so:

Using Rickshaw

Note: This is subject to future change because it would be better to use playground for this purpose.

WISP

WISP is really easy to use to draw plots, however a simple wrapper has been created to ease the integration.

First import the helper:

import notebook.front.third.wisp._

Here is how you can draw an area chart:

Plot(Seq(SummarySeries((0 to 9) zip (10 to 100 by 10), "area")))

And a bar plot with category values

import com.quantifind.charts.highcharts.Axis
Plot(Seq(SummarySeries((0 to 9) zip (10 to 100 by 10), "column")),
    xCat = Some(Seq("a", "b", "c", "d", "e", "f", "g", "h", "i", "j"))
)

Timeseries with Rickshaw

Plotting timeseries is very common, for this purpose the spark notebook includes Rickshaw that quickly enables handsome timeline charts.

Rickshaw is available through Playground and a dedicated function for simple needs rickshawts.

To use it, you are only required to convert/wrap your data points into a dedicated Series object:

def createTss(start:Long, step:Int=60*1000, nb:Int = 100):Seq[Series] = ...
val data = createTss(orig, step, nb)

val p = new Playground(data, List(Script("rickshawts",
                                          Json.obj(
                                            "renderer"  "stack",
                                            "fixed"  Json.obj(
                                                        "interval"  (step/1000),
                                                        "max"  100,
                                                        "baseInSec"  (orig/1000)
                                                      )
                                          ))))(seriesCodec)

As you can see, the only big deal is to create the timeseries (Seq[Series] which is a simple wrapper around:

  • name
  • color
  • data (a sequence of x and y)

Also, there are some options to tune the display:

  • provide the type of renderer (line, stack, …)
  • if the timeseries will be updated you can fix the window by supplying the fixed object:
  • interval (at which data is upated)
  • max (the max number of points displayed)
  • the unit in the X axis.

Here is an example of the kind of result you can expect:

Using Rickshaw

Dynamic update of data and plot using Scala’s Future

One of the very cool things that is used in the original scala-notebook is the use of reactive libs on both sides: server and client, combined with WebSockets. This offers a neat way to show dynamic activities like streaming data and so on.

We can exploit the reactive support to update Plot wrappers (the Playground instance actually) in a dynamic manner. If the JS functions are listening to the data changes they can automatically update their result.

The following example is showing how a timeseries plotted with Rickshaw can be regularly updated. We are using Scala Futures to simulate a server side process that would poll for a third-party service:

Update Timeseries Result

The results will be:

Update Timeseries Result

Update Notebook ClassPath

Keeping your notebook runtime updated with the libraries you need in the classpath is usually cumbersome as it requires updating the server configuration in the SBT definition and restarting the system. Which is pretty sad because it requires a restart, rebuild and is not contextual to the notebook!

Hence, a dedicated context has been added to the block, :cp which allows us to add specifiy local paths to jars that will be part of the classpath.

:cp /home/noootsab/.m2/repository/joda-time/joda-time/2.4/joda-time-2.4.jar

Or even

:cp
/tmp/scala-notebook/repo/com/codahale/metrics/metrics-core/3.0.2/metrics-core-3.0.2.jar
/tmp/scala-notebook/repo/org/scala-lang/scala-compiler/2.10.4/scala-compiler-2.10.4.jar
/tmp/scala-notebook/repo/org/scala-lang/scala-library/2.10.4/scala-library-2.10.4.jar
/tmp/scala-notebook/repo/joda-time/joda-time/2.3/joda-time-2.3.jar
/tmp/scala-notebook/repo/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar
/tmp/scala-notebook/repo/com/datastax/cassandra/cassandra-driver-core/2.0.4/cassandra-driver-core-2.0.4.jar
/tmp/scala-notebook/repo/org/apache/thrift/libthrift/0.9.1/libthrift-0.9.1.jar
/tmp/scala-notebook/repo/org/apache/httpcomponents/httpcore/4.2.4/httpcore-4.2.4.jar
/tmp/scala-notebook/repo/org/joda/joda-convert/1.2/joda-convert-1.2.jar
/tmp/scala-notebook/repo/org/scala-lang/scala-reflect/2.10.4/scala-reflect-2.10.4.jar
/tmp/scala-notebook/repo/org/apache/cassandra/cassandra-clientutil/2.0.9/cassandra-clientutil-2.0.9.jar
/tmp/scala-notebook/repo/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.jar
/tmp/scala-notebook/repo/com/datastax/cassandra/cassandra-driver-core/2.0.4/cassandra-driver-core-2.0.4-sources.jar
/tmp/scala-notebook/repo/io/netty/netty/3.9.0.Final/netty-3.9.0.Final.jar
/tmp/scala-notebook/repo/org/apache/commons/commons-lang3/3.3.2/commons-lang3-3.3.2.jar
/tmp/scala-notebook/repo/commons-codec/commons-codec/1.6/commons-codec-1.6.jar
/tmp/scala-notebook/repo/org/apache/httpcomponents/httpclient/4.2.5/httpclient-4.2.5.jar
/tmp/scala-notebook/repo/org/apache/cassandra/cassandra-thrift/2.0.9/cassandra-thrift-2.0.9.jar
/tmp/scala-notebook/repo/com/datastax/spark/spark-cassandra-connector_2.10/1.1.0-alpha1/spark-cassandra-connector_2.10-1.1.0-alpha1.jar
/tmp/scala-notebook/repo/com/google/guava/guava/15.0/guava-15.0.jar

Here is what it’ll look like in the notebook:

Simple Classpath

Update Spark dependencies (spark.jars)

So you use Spark, hence you know that it’s not enough to have the jars locally added to the Driver’s classpath.

Indeed, workers needs to have them in their classpath. One option would be to update the list of jars (spark.jars property) provided to the SparkConf using the reset function.

However, this can be very tricky when we need to add jars that have themselves plenty of dependencies.

Thus, there is another context available to update both the classpath on the notebook and in Spark. Before introducing it, we need first to introduce two other concepts.

Set local-repo

When updating you dependencies, you can either leave the system create a repo (temporary) for you where it’ll fetch the dependencies.

Or, you can set it yourself by using the :local-repo this way:

:local-repo /path/to/repo

This way, you can reuse local dependencies or reuse pre-downloaded ones.

Add remote-repo

To instruct the system where to look for dependencies, you’ll have to use the :remote-repo context:

:remote-repo oss-sonatype % default % https://oss.sonatype.org/content/repositories/releases/

Above we defined a repo named oss-sonatype with default structure at localtion https://oss.sonatype.org/content/repositories/releases/.

remote-repo with authentication

Some repos (on S3 for instance) require authentication, for this you can add them literally or using env variables:

:remote-repo :remote-repo s3-repo % default % s3://<bucket-name>/<path-to-repo> % ("$AWS_ACCESS_KEY_ID", "$AWS_SECRET_ACCESS_KEY")

Download and add dependencies

So to add dependencies based on the context that has been set using the above contexts can be done using :dp.

:dp
+ group1 % artifact1 % version1
+ group2 % artifact2 % version2
group3 % artifact3 % version3
+ group4 % artifact4 % version4

- group5 % artifact5 % version5
+ group6 % artifact6 % version6
- group7 % artifact7 % version7

So this is simple:

  • lines starting with - are exclusions (transitive)
  • lines starting with + or nothing are inclusions

The jars will be fetched in a temporary repository (that can be hardcoded using :local-repo).

Then they’ll be added to the Spark’s jars property, before restarting the context.

For example, if you want to use ADAM, all you need to do is:

:dp org.bdgenomics.adam % adam-apis % 0.16.0
- org.apache.hadoop % hadoop-client %   _
- org.apache.spark  %     _         %   _
- org.scala-lang    %     _         %   _
- org.scoverage     %     _         %   _

In live, you can check the notebook named Update classpath and Spark's jars, which looks like this:

Spark Jars

TIPS AND TROUBLESHOOTING

There are some common problems that users experience from time to time. So we collected some useful tips to make your life easier:

  • spark-notebook uses old hadoop 1.0.4 by default. As notebook is a spark-driver itself, hence it defines the dependencies to be used within the cluster. This means that the hadoop-client has to match the cluster one, that’s why we need to start the correct hadoop version in (or download the right distro), you should start spark-notebook with -Dhadoop.version parameter, like:
    sbt -Dhadoop.version=2.4.0 run
    
  • many errors are not yet reported directly to notebook console. So, if something is wrong do not forget to look at logs/sn-session.log and at spark worker’s logs.
  • your current spark configuration is shown in Edit > Edit Notebook Metadata. You can make changes there instead of adding a special cell for reseting default spark configuration. You can also create a template for spark configuration in a “Clusters” tab.
  • some features (like switching output modes of the cell) are activated by keyboard shortcuts that are described at Help > Keyboard Shortcuts.

IMPORTANT

Some vizualizations (wisp) are currently using Highcharts which is not available for commercial or private usage!

If you’re in this case, please to contact me first.

KNOWN ISSUES

User limit of inotify watches reached

When running Spark-Notebook on some Linux distribs (specifically ArchLinux), you may encounter this exception:

[spark-notebook] $ run

java.io.IOException: User limit of inotify watches reached
at sun.nio.fs.LinuxWatchService$Poller.implRegister(LinuxWatchService.java:261)
at sun.nio.fs.AbstractPoller.processRequests(AbstractPoller.java:260)
at sun.nio.fs.LinuxWatchService$Poller.run(LinuxWatchService.java:326)
at java.lang.Thread.run(Thread.java:745)
[trace] Stack trace suppressed: run last sparkNotebook/compile:run for the full output.
[error] (sparkNotebook/compile:run) java.lang.reflect.InvocationTargetException
[error] Total time: 1 s, completed Jan 31, 2015 7:21:58 PM

This certainly means your sysctl configuration limits too much inotify watches.

You must increase the parameter fs.inotify.max_user_watches.

To get current value:

$ sudo sysctl -a | grep fs.inotify.max_user_watches
fs.inotify.max_user_watches = 8192

To increase this value, create a new file /etc/sysctl.d99-sysctl.conf

fs.inotify.max_user_watches=100000

Refresh your live sysctl configuration:

$ sudo sysctl --system

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