Cassandra Cloud

CassandraCloud is a tool that helps you configure Cassandra for clustered environments. It works well in Docker, EC2, and VirtualBox environments (and similar environments). It allows you to configure Cassandra easily. For example, it could be kicked off as a USER_DATA script in Amazon EC2 (AWS EC2). CassandraCloud usually runs once when an instance is first launched and then never again.

Config Overrides and Templates

CassandraCloud allows you to override values via OS ENVIRONMENT variables. There is an HCL config file, and there are command line arguments.

The HCL config file can be overridden with ENVIRONMENT which can be overridden with command line arguments.

CassandraCloud will generate ${CASSANDRA_HOME}/conf/cassandra.yaml file. You can specify a custom template (usually found in ${CASSANDRA_HOME}/conf/cassandra-yaml.template).

Example ${CASSANDRA_HOME}/conf/cassandra-yaml.template

cluster_name: "{{.ClusterName}}"
num_tokens: {{.NumTokens}}
storage_port: {{.ClusterPort}}
ssl_storage_port: {{.ClusterSslPort}}
native_transport_port: {{.ClientPort}}
endpoint_snitch: {{.Snitch}}

{{if .ClientListenAddress}}# Listen address for client communication
rpc_address: {{.ClientListenAddress}}{{end}}
{{if .ClientListenInterface}}# Listen network interface for client communication
rpc_interface: {{.ClientListenInterface}}{{end}}


{{if .ClusterListenAddress}}# Listen address for storage cluster communication
listen_address: {{.ClusterListenAddress}}{{end}}
{{if .ClusterListenInterface}}# Listen network interface for storage cluster communication
listen_interface: {{.ClusterListenInterface}}{{end}}

{{if .MultiDataCenter}}max_hints_delivery_threads: 16{{else}}max_hints_delivery_threads: 2{{end}}


data_file_directories:
{{range .DataDirs}}     - {{.}}{{end}}

commitlog_directory: {{.CommitLogDir}}

To learn the complete syntax of the template this template syntax guide.

The above could generate a cassandra.yaml file as follows:

cassandra.yaml

cluster_name: "My Cluster"
num_tokens: 32
storage_port: 7000
ssl_storage_port: 7001
native_transport_port: 9042
endpoint_snitch: SimpleSnitch


# Listen network interface for client communication
rpc_interface: localhost



# Listen network interface for storage cluster communication
listen_interface: localhost

max_hints_delivery_threads: 2


data_file_directories:
     - /opt/cassandra/data

commitlog_directory: /opt/cassandra/commitlog


seed_provider:
    - class_name: org.apache.cassandra.locator.SimpleSeedProvider
      parameters:
          - seeds: "127.0.0.1"

There are also templates for jvm.options, cassandra-env.sh, and logback.xml.

Usage

./cassandra-cloud  -h
  -client-address string
        Client address for client driver communication. Example: 192.43.32.10, localhost, etc. (default "localhost")
  -client-interface string
        Client address for client driver communication. Example: eth0, eth1, etc.
  -cluster-address string
        Cluster address for inter-node communication. Example: 192.43.32.10, localhost, etc. (default "localhost")
  -cluster-interface string
        Cluster interface for inter-node communication.  Example: eth0, eth1, etc.
  -cluster-name string
        Name of the cluster (default "My Cluster")
  -cluster-seeds string
        Comma delimited list of initial clustrer contact points for bootstrapping (default "127.0.0.1")
  -cms-young-gen-size string
        If using CMS as GC, selects the proper size for the CMS YoungGen. Set this to a specific size of AUTO for environment ergonomics (default "800MB")
  -conf-jvm-options-file string
        JVM Option location which will be overwritten with template. (default "/opt/cassandra/conf/jvm.options")
  -conf-jvm-options-template string
        JVM Option template location. Used to generate the jvm.options file using system ergonomics. (default "/opt/cassandra/conf/jvm-options.template")
  -conf-yaml-template string
        Location of cassandra configuration template (default "/opt/cassandra/conf/cassandra-yaml.template")
  -config string
        Location of config file
  -data-dirs string
        Location of Cassandra Data directories
  -debug
        Turn on debugging
  -g1-concurrent-threads string
        The count of G1 Parallel threads. Values: AUTO, or some number. Uses ergonomics to pick a number (default "8")
  -g1-parallel-threads string
        The count of G1 Parallel threads. Values: AUTO, or some number. Uses ergonomics to pick a thread count (default "8")
  -gc string
        GC type. Values: CMS, G1, or AUTO. If you set to AUTO, if heap is bigger than 5 GB (gc-g1-threshold-gbs), G1 is used, otherwise CMS. (default "GC1")
  -gc-g1-threshold-gbs int
        GC threshold switch. Defaults to 5 GB. If gc set to AUTO, if heap is bigger than gc-g1-threshold-gbs, G1 is used, otherwise CMS. (default 5)
  -gc_stats_enabled
        Enable logging GC stats from JVM.
  -help-info
        Prints out help information
  -max-heap-size string
        Sets the MaxHeapSize using a size string, i.e., 10GB or uses AUTO to enable system environment ergonomics. (70% of free heap) (default "4859MB")
  -min-heap-size string
        Sets the MaxHeapSize using a size string, i.e., 10GB or uses AUTO to enable system environment ergonomics. (Set to MaxHeapSize) (default "4859MB")
  -snitch string
        Snitch type. Example: GossipingPropertyFileSnitch, PropertyFileSnitch, Ec2Snitch, etc. (default "SimpleSnitch")
  -v    Turns on verbose mode

Command line flag syntax:

-flag
-flag=x
-flag x  // non-boolean flags only

Configuration

Cloud conf usually found in ${CASSANDRA_HOME}/conf/cloud.conf


# Defaults to false. Used for verbose mode.
# verbose = false

# Comma delimited list of seed hosts. Defaults to 127.0.0.1. This is used for bootstrap only.
# Production clusters should have at least two seed servers.
# cluster_seeds = 127.0.0.1

# Cassandra home directory. Defaults to /opt/cassandra.
# home_dir = /opt/cassandra

# Are we supporting multiple DCs? Defaults to false.
# multi_dc = false

# Only one of these two can be set (defaults to address set to localhost Linux)
# cluster_address = localhost
# cluster_interface=eth1

# Only one of these two can be set (defaults to address set to localhost for OSX and interface set to eth0 for Linux)
# client_address=localhost
# client_interface=eth0

# Sets the snitch type for Cassandra. Defaults to simple snitch (for now).
# snitch=SimpleSnitch

# Sets up VNODE weight for servder. Defaults to 32 tokens per node
# num_tokens=32

# Location of template file. Defaults to {{home_dir}}/conf/cassandra-yaml.template
# conf_yaml_template = /opt/cassandra/conf/cassandra-yaml.template

# Location of cassandra config yaml file that we want to replace.
# Defaults to {{home_dir}}/conf/cassandra.yaml
# conf_yaml_file = /opt/cassandra/conf/cassandra.yaml

# Cluster port. Defaults to 7000.
# cluster_port = 7000
# Cluster SSL port. Defaults to 7001.
# cluster_ssl_port = 7001

# Client port. Defaults to 9042.
# client_port = 9042

# Data directories for Cassandra SSTables. Defaults to ["/opt/cassandra/data"]
# data_dirs = ["/opt/cassandra/data"]

Template variable (types, and how to override them)

The table below lists the variable names. A setting in the config file (Config Name) overrides the default value(Default Value). Environment Variables override config file settings (Config Name). Lastly values passed on the command line (Command line Args) override the config.

The Template Var Names are used by the templates.

For example the CommitLogDir template var can be used in a template by referring to it as {{.CommitLogDir}}.

Template Var Name	Type	Config Name	Command line	Environment Variable	Default Value
DataDirs	[]string	data_dirs	-data-dirs	CASSANDRA_DATA_DIRS	[/opt/cassandra/data ]
CassandraHome	string	home_dir	-home-dir	CASSANDRA_HOME_DIR	/opt/cassandra
ClusterSeeds	string	cluster_seeds	-cluster-seeds	CASSANDRA_CLUSTER_SEEDS	127.0.0.1
ClusterListenAddress	string	cluster_address	-cluster-address	CASSANDRA_CLUSTER_ADDRESS	localhost
ClusterListenInterface	string	cluster_interface	-cluster-interface	CASSANDRA_CLUSTER_INTERFACE
ClientListenAddress	string	client_address	-client-address	CASSANDRA_CLIENT_ADDRESS	localhost
ClientListenInterface	string	client_interface	-client-interface	CASSANDRA_CLIENT_INTERFACE
ClientPort	int	client_port	-client-port	CASSANDRA_CLIENT_PORT	9042
ClusterName	string	cluster_name	-cluster-name	CASSANDRA_CLUSTER_NAME	My Cluster
ClusterPort	int	cluster_port	-cluster-port	CASSANDRA_CLUSTER_PORT	7000
ClusterSslPort	int	cluster_ssl_port	-cluster-ssl-port	CASSANDRA_CLUSTER_SSL_PORT	7001
CmsYoungGenSize	string	cms_young_gen_size	-cms-young-gen-size	CASSANDRA_CMS_YOUNG_GEN_SIZE	800MB
CommitLogDir	string	commit_log_dir	-commit-log-dir	CASSANDRA_COMMIT_LOG_DIR	/opt/cassandra/commitlog
GCStatsEnabled	bool	gc_stats_enabled	-gc-stats-enabled	CASSANDRA_GC_STATS_ENABLED	false
GC	string	gc	-gc	CASSANDRA_GC	GC1 if over 5GB heap free
G1ThresholdGBs	int	gc_g1_threshold_gbs	-gc-g1-threshold-gbs	CASSANDRA_GC_G1_THRESHOLD_GBS	5
G1ParallelGCThreads	string	g1_parallel_threads	-g1-parallel-threads	CASSANDRA_G1_PARALLEL_THREADS	8
G1ConcGCThreads	string	g1_concurrent_threads	-g1-concurrent-threads	CASSANDRA_G1_CONCURRENT_THREADS	8
JvmOptionsFileName	string	conf_jvm_options_file	-conf-jvm-options-file	CASSANDRA_CONF_JVM_OPTIONS_FILE	/opt/cassandra/conf/jvm.options
JvmOptionsTemplate	string	conf_jvm_options_template	-conf-jvm-options-template	CASSANDRA_CONF_JVM_OPTIONS_TEMPLATE	/opt/cassandra/conf/jvm-options.template
MinHeapSize	string	min_heap_size	-min-heap-size	CASSANDRA_MIN_HEAP_SIZE	4859MB
MaxHeapSize	string	max_heap_size	-max-heap-size	CASSANDRA_MAX_HEAP_SIZE	4859MB
MultiDataCenter	bool	multi_dc	-multi-dc	CASSANDRA_MULTI_DC	false
NumTokens	int	num_tokens	-num-tokens	CASSANDRA_NUM_TOKENS	32
Snitch	string	snitch	-snitch	CASSANDRA_SNITCH	SimpleSnitch
Verbose	bool	verbose	-verbose	CASSANDRA_VERBOSE	false
YamlConfigTemplate	string	conf_yaml_template	-conf-yaml-template	CASSANDRA_CONF_YAML_TEMPLATE	/opt/cassandra/conf/cassandra-yaml.template
YamlConfigFileName	string	conf_yaml_file	-conf-yaml-file	CASSANDRA_CONF_YAML_FILE	/opt/cassandra/conf/cassandra.yaml

About us

Cloudurable provides AMIs, cloudformation templates and monitoring tools to support Cassandra in production running in EC2. We also teach advanced Cassandra courses which teaches how one could develop, support and deploy Cassandra to production in AWS EC2.

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