Package: ccm
CCM (Cassandra Cluster Manager)A script/library to create, launch and remove an Apache Cassandra cluster on
localhost.The goal of ccm and ccmlib is to make it easy to create, manage and destroy a
small Cassandra cluster on a local box. It is meant for testing a Cassandra cluster.RequirementsA working python installation (tested to work with python 2.7).pyYAML (http://pyyaml.org/--sudo easy_install pyYaml)six (https://pypi.org/project/six/--sudo easy_install six)ant (http://ant.apache.org/, on Mac OS X,brew install ant)psutil (https://pypi.org/project/psutil/)Java (which version depends on the version of Cassandra you plan to use. If
unsure, use Java 7 as it is known to work with current versions of Cassandra).If you want to create multiple node clusters, the simplest way is to use
multiple loopback aliases. On modern linux distributions you probably don't
need to do anything, but on Mac OS X, you will need to create the aliases withsudo ifconfig lo0 alias 127.0.0.2 up
sudo ifconfig lo0 alias 127.0.0.3 up
...Note that the usage section assumes that at least 127.0.0.1, 127.0.0.2 and
127.0.0.3 are available.Optional RequirementsParamiko (http://www.paramiko.org/): Paramiko adds the ability to execute CCM
remotely;pip install paramikoNote: The remote machine must be configured with an SSH server and a working
CCM. When working with multiple nodes each exposed IP address must be
in sequential order. For example, the last number in the 4th octet of
a IPv4 address must start with1(e.g. 192.168.33.11). SeeVagrantfilefor help with configuration of remote
CCM machine.Known issuesWindows only:node startpops up a window, stealing focus.cqlsh started from ccm show incorrect prompts on command-promptnon nodetool-based command-line options fail (sstablesplit, scrub, etc)To install psutil, you must use the .msi from pypi. pip install psutil will not workYou will need ant.bat in your PATH in order to build C* from sourceYou must run with an Unrestricted Powershell Execution-Policy if using Cassandra 2.1.0+Ant installed viachocolateywill not be found by ccm, so you must create a symbolic
link in order to fix the issue (as administrator):cmd /c mklink C:\ProgramData\chocolatey\bin\ant.bat C:\ProgramData\chocolatey\bin\ant.exeRemote Execution only:Using--config-dirand--install-dirwithcreatemay not work as
expected; since the configuration directory and the installation directory
contain lots of files they will not be copied over to the remote machine
like most other options for cluster and node operationscqlsh started from ccm using remote execution will not start
properly (e.g.ccm --ssh-host 192.168.33.11 node1 cqlsh); however-x <CMDS>or--exec=CMDScan still be used to execute a CQLSH command
on a remote node.Installationccm uses python distutils so from the source directory run:sudo ./setup.py installccm is available on thePython Package Index:pip install ccmThere is also aHomebrew packageavailable:brew install ccmUsageLet's say you wanted to fire up a 3 node Cassandra cluster.Short versionccm create test -v 2.0.5 -n 3 -sYou will of course want to replace2.0.5by whichever version of Cassandra
you want to test.Longer versionccm works from a Cassandra source tree (not the jars). There are two ways to
tell ccm how to find the sources:If you have downloadedandcompiled Cassandra sources, you can ask ccm
to use those by initiating a new cluster with:ccm create test --install-dir=<path/to/cassandra-sources>or, from that source tree directory, simplyccm create testYou can ask ccm to use a released version of Cassandra. For instance to
use Cassandra 2.0.5, runccm create test -v 2.0.5ccm will download the binary (fromhttp://archive.apache.org/dist/cassandra),
and set the new cluster to use it. This means
that this command can take a few minutes the first time you
create a cluster for a given version. ccm saves the compiled
source in~/.ccm/repository/, so creating a cluster for that
version will be much faster the second time you run it
(note however that if you create a lot of clusters with
different versions, this will take up disk space).Once the cluster is created, you can populate it with 3 nodes with:ccm populate -n 3For Mac OSX, create a new interface for every node besides the first, for example if you populated your cluster with 3 nodes, create interfaces for 127.0.0.2 and 127.0.0.3 like so:sudo ifconfig lo0 alias 127.0.0.2
sudo ifconfig lo0 alias 127.0.0.3Note these aliases will disappear on reboot. For permanent network aliases on Mac OSX see.After that execute:ccm startThat will start 3 nodes on IP 127.0.0.[1, 2, 3] on port 9160 for thrift, port
7000 for the internal cluster communication and ports 7100, 7200 and 7300 for JMX.
You can check that the cluster is correctly set up withccm node1 ringYou can then bootstrap a 4th node withccm add node4 -i 127.0.0.4 -j 7400 -b(populate is just a shortcut for adding multiple nodes initially)ccm provides a number of conveniences, like flushing all of the nodes of
the cluster:ccm flushor only one node:ccm node2 flushYou can also easily look at the log file of a given node with:ccm node1 showlogFinally, you can get rid of the whole cluster (which will stop the node and
remove all the data) withccm removeThe list of other provided commands is available throughccmEach command is then documented through the-h(or--help) flag. For
instanceccm add -hdescribes the options forccm add.Remote Usage (SSH/Paramiko)All the usage examples above will work exactly the same for a remotely
configured machine; however remote options are required in order to establish a
connection to the remote machine before executing the CCM commands:ArgumentValueDescription--ssh-hoststringHostname or IP address to use for SSH connection--ssh-portintPort to use for SSH connectionDefault is 22--ssh-usernamestringUsername to use for username/password or public key authentication--ssh-passwordstringPassword to use for username/password or private key passphrase using public key authentication--ssh-private-keyfilenamePrivate key to use for SSH connectionSpecial HandlingSome commands require files to be located on the remote server. Those commands
are pre-processed, file transfers are initiated, and updates are made to the
argument value for the remote execution of the CCM command:ParameterDescription--dse-credentialsCopy local DSE credentials file to remote server--node-sslRecursively copy node SSL directory to remote server--sslRecursively copy SSL directory to remote serverShort Versionccm --ssh-host=192.168.33.11 --ssh-username=vagrant --ssh-password=vagrant create test -v 2.0.5 -n 3 -i 192.168.33.1 -sNote:-iis used to add an IP prefix during the create process to ensure
that the nodes communicate using the proper IP address for their nodeSource DistributionIf you'd like to use a source distribution instead of the default binary each time (for example, for Continuous Integration), you can prefix cassandra version withsource:, for example:ccm create test -v source:2.0.5 -n 3 -sAutomatic Version FallbackIf 'binary:' or 'source:' are not explicitly specified in your version string, then ccm will fallback to building the requested version from git if it cannot access the apache mirrors.Git and GitHubTo use the latest version from thecanonical Apache Git repository, use the version namegit:branch-name, e.g.:ccm create trunk -v git:trunk -n 5and to download a branch from a GitHub fork of Cassandra, you can prefix the repository and branch withgithub:, e.g.:ccm create patched -v github:jbellis/trunk -n 1Bash command-line completionccm has many sub-commands for both cluster commands as well as node commands, and sometimes you don't quite remember the name of the sub-command you want to invoke. Also, command lines may be long due to long cluster or node names.Leverage bash'sprogrammable completionfeature to make ccm use more pleasant. Copymisc/ccm-completion.bashto somewhere in your home directory (or /etc if you want to make it accessible to all users of your system) and source it in your.bash_profile:. ~/scripts/ccm-completion.bashOnce set up,ccm sw<tab>expands toccm switch, for example. Theswitchsub-command has extra completion logic to help complete the cluster name. Soccm switch cl<tab>would expand toccm switch cluster-58if cluster-58 is the only cluster whose name starts with "cl". If there is ambiguity, hitting<tab>a second time shows the choices that match:$ ccm switch cl<tab>
    ... becomes ...
$ ccm switch cluster-
    ... then hit tab twice ...
cluster-56  cluster-85  cluster-96
$ ccm switch cluster-8<tab>
    ... becomes ...
$ ccm switch cluster-85It dynamically determines available sub-commands based on the ccm being invoked. Thus, users running multiple ccm's (or a ccm that they are continuously updating with new commands) will automagically work.The completion script relies on ccm having two hidden subcommands:show-cluster-cmds - emits the names of cluster sub-commands.show-node-cmds - emits the names of node sub-commands.Thus, it will not work with sufficiently old versions of ccm.Remote debuggingIf you would like to connect to your Cassandra nodes with a remote debugger you have to pass the-d(or--debug) flag to the populate command:ccm populate -d -n 3That will populate 3 nodes on IP 127.0.0.[1, 2, 3] setting up the remote debugging on ports 2100, 2200 and 2300.
The main thread will not be suspended so you don't have to connect with a remote debugger to start a node.Alternatively you can also specify a remote port with the-r(or--remote-debug-port) flag while adding a nodeccm add node4 -r 5005 -i 127.0.0.4 -j 7400 -bWhere things are storedBy default, ccm stores all the node data and configuration files under~/.ccm/cluster_name/.
This can be overridden using the--config-diroption with each command.DataStax EnterpriseCCM 2.0 supports creating and interacting with DSE clusters. The --dse
option must be used with theccm createcommand. See theccm create -hhelp for assistance.CCM LibThe ccm facilities are available programmatically through ccmlib. This could
be used to implement automated tests against Cassandra. A simple example of
how to use ccmlib follows:import ccmlib.cluster

CLUSTER_PATH="."
cluster = ccmlib.cluster.Cluster(CLUSTER_PATH, 'test', cassandra_version='2.1.14')
cluster.populate(3).start()
[node1, node2, node3] = cluster.nodelist()

# do some tests on the cluster/nodes. To connect to a node through thrift,
# the host and port to a node is available through
#   node.network_interfaces['thrift']

cluster.flush()
node2.compact()

# do some other tests

# after the test, you can leave the cluster running, you can stop all nodes
# using cluster.stop() but keep the data around (in CLUSTER_PATH/test), or
# you can remove everything with cluster.remove()--
Sylvain Lebresnesylvain@datastax.com