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CRS Configuration Options

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The Connected Runtime Service (CRS) is the component inside the JVM that runs your applications or in the Intelligence Cloud Agent that runs next to your applications. CRS collects the dependency information of your application, and sends it via the Forwarder to Azul Intelligence Cloud. On this page, you find all the configuration options for normal usage. Next to these options, there are also Diagnostics Configuration Options.

CRS Mode

Note
 This configuration option is only applicable when you use an Azul JDK or JRE. It’s not available for the Azul Intelligence Cloud Agent.

The CRS Mode can be configured with the -XX:AzCRSMode startup argument and has the following options:

  • auto: This is the default value. CRS decides whether it needs to start in the main method, and excludes tools like javap, javac having a specific main method in com.sun.tools.

  • on: Forces CRS to start, if all required configurations are available (e.g. endpoint), even for tools like javap, javac.

  • off: Forces CRS to be disabled.

Usage Example

 
java -XX:AzCRSMode=on -jar MyApp.jar

CRS Runtime Instance Tags

A runtime tag is a user-defined key-value pair that is associated with an instance. Tags are used to search, categorize, and organize instances logically in the Azul Intelligence Cloud Web UI. Unlike instance IDs, tags are not unique. You can add the same tag to multiple instances as well as add multiple tags to one instance.

Applying Tags

Tag keys must begin with a letter. Both key and value may contain lower and upper case letters, and numbers. These additional characters are also allowed:

 
ALLOWED_KEY_EXTRA_CHARS = "-_."
ALLOWED_VALUE_EXTRA_CHARS = "-_. :/@" <-- Includes space
Note
 Tags can be provided both as environment variable and in command line options. When using both, the results are combined. It’s recommended to use environment variables as it allows AZ_CRS_ARGUMENTS to be mostly the same for each JVM.

Special Tags

This tag is handled in a specific way with the system:

Tag Description Example

AppEnv

To use the "Code Inventory Summarization" feature, you need to configure an AppEnv value on the machine where you run the JVM. The value is, for example, the application name. This information is sent through the Forwarder to the Azul Intelligence Cloud system, together with information about the components, classes, and methods that are used.

AppEnv=test

How to Use Tags

Tags can be specified with a command line argument or environment variable:

 
# With command line option
-Dcom.azul.crs.instance.tags="system-prop.tag_1=system prop/value@1; system_prop_tag.2=system prop:value/2"

# With environment variable
export CRS_TAGS="env.tag-1=value:1; env_Tag_2=value 2"

For example, using the command line option:

 
java -XX:AzCRSMode=on \
    -XX:AzCRSArguments=api.url={forwarder_endpoint} \
    -Dcom.azul.crs.instance.tags="AppEnv=MyApplicationTag" \
    -jar MyApp.jar

It is important that you properly tag your instances. As a general rule, tagging should reflect the way you categorize your Java applications. For example, you can use "west-coast", "east-coast", and so on to distinguish between different availability zones/locations.

Note
 Some instance properties are detected automatically. For example, you don’t have to tag Java versions, because it’s detected by CRS.

CRS Arguments

CRS can be controlled with the following arguments. They need to be specified in a comma-separated value format. Each expression is either <propertyName>=<value>, or just <propertyName> for Boolean properties. These are the available properties:

Argument Default Description

props

~/.az_crs/config.properties

Location of a properties file to configure CRS.

api.url

null

This is the base URL of your Forwarder instance. If null, your runtime performs a DNS-based lookup to locate its Forwarder. If no Forwarder is specified anywhere, CRS is effectively disabled.

The Forwarder endpoint must be in URL format, e.g. https://FORWARDER_IP:443.

enable

true

Use this argument when you can’t adjust the command line, to enable or disable the CRS agent. Enabling the CRS agent with enable=true has the same effect as -XX:AzCRSMode=auto.

Note
 When you specify the -XX:AzCRSMode runtime flag, this enable environment variable flag, gets ignored.

delayTermination

0

Number of milliseconds to hold a JVM alive at its end, providing time to send the collected data to the Forwarder. Raise the value to provide time to short-lived microservices. The provided value is used as a maximum, if CRS takes less time (down to 0), the delay doesn’t use the fully defined duration.

delayInitiation

2000

Number of milliseconds to delay the CRS start. The default enables integration with major Java frameworks. Lower to 0 for short-lived microservices.

stackRecordId

null

Suffix of the DNS record to query for an endpoint.

sendPOMData

true

Flag to define if the content of pom.properties files must be sent to Intelligence Cloud.

log

error

The level of logging for CRS. Options are (case insensitive): trace, debug, info, warning, error, off. The use of the trace level is discouraged, since this leads to enormous sized output.

If you want to see all messages logged by all services and monitors, you need to use, for instance, log=info to get all info messages. You can further extend the logged messages, by specifying the service or monitor. These are the available options:

  • args

  • connection

  • connection.pinger

  • id

  • inventory

  • mainMethod.detect

  • performance

  • requests.processor

  • service.classload

  • service.classloadevent

  • service.classload.loaderwrapper

  • service.classload.loaderlogger

  • service.event

  • service.filetailer

  • service.firstcall

  • service.gclog

  • service.heartbeat

  • service.jarload

  • service.jarload.ziptools

  • service.jarload.reporter

  • service.jfr

  • service.queue

  • service.systeminfo

  • service.upload

  • service.vmlog

  • service.vmtooling

  • utils

  • vmsupport

You can combine several configurations, for instance, log=info,log+connection=trace to get all info messages plus the trace messages related to the connection.

keystore

null

If set, this keystore is used to authenticate the JVM with the Forwarder. Set this to a Java Keystore file when using self-signed certificates.

Usage Examples

 
# Environment variable for Azul Intelligence Cloud Agent
export JDK_JAVA_OPTIONS="-javaagent:${AGENTDIR}/ic-agent.jar,expression1,expression2,expression3 \
  -DaagentDir=${AGENTDIR} \
  -Djava.security.policy=${AGENTDIR}/agent.all.policy"

# Command line option for Azul JDK or JRE
java -XX:AzCRSArguments=expression1,expression2,expression3 -jar MyApp.jar

# Environment variable for Azul JDK or JRE
export AZ_CRS_ARGUMENTS=expression1,expression2,expression3

Where to Specify Configurations

Depending on how you run your Java applications to send data through the Forwarder to Azul Intelligence Cloud, several options are available to configure your runtimes.

Azul Intelligence Cloud Agent

For the Azul Intelligence Cloud Agent, both Tags and Arguments are is configured with environment variables. Tags are defined with CRS_TAGS, while arguments are added in the agent configuration with JDK_JAVA_OPTIONS.

 
export CRS_TAGS=YOUR_CRS_TAGS
export JDK_JAVA_OPTIONS="-javaagent:${AGENTDIR}/ic-agent.jar,YOUR_CRS_ARGUMENTS \
  -DaagentDir=${AGENTDIR} \
  -Djava.security.policy=${AGENTDIR}/agent.all.policy"

For example:

 
export CRS_TAGS="env.tag-1=value:1; env_Tag_2=value 2"
export JDK_JAVA_OPTIONS="-javaagent:${AGENTDIR}/ic-agent.jar,sendPOMData=false,log=info \
  -DaagentDir=${AGENTDIR} \
  -Djava.security.policy=${AGENTDIR}/agent.all.policy"

Azul JDK or JRE Runtime

To enable and configure your instances running with an Azul runtime and CRS, you can choose to use one of these three options:

  1. JVM command line arguments

  2. The AZ_CRS_ARGUMENTS and CRS_TAGS environment variables

  3. A .properties file

The connected runtime looks for the configuration parameters in the order described above. You can use a combination of these options. If you set a parameter in several ways, for example via both the environment variable and configuration file, the JVM uses the value that comes first in the order given above.

In addition, the Forwarder address can be configured via DNS records. See Service discovery via DNS.

JVM Command Line Arguments

Pass configuration parameters to the CRS (Connected Runtime Service) in the Azul JVM by using the -XX:AzCRSArguments command line argument:

Minimal command that sets the api.url parameter via JVM arguments.:
 
java -XX:AzCRSMode=on \
    -XX:AzCRSArguments=api.url={forwarder_endpoint} \
    MyApp
A more extended example via JVM arguments:
 
java -XX:AzCRSMode=on \
    -XX:AzCRSArguments=api.url={forwarder_endpoint},log=debug,delayTermination=120000,delayInitiation=0 \
    -Dcom.azul.crs.instance.tags={tags} \
    MyApp

Environment Variables

You can use dedicated environment variables to enable and control all JVM processes for Azul Zulu and Zing distributions. When the environment variables are present, they automatically apply to any newly started JVM, enabling CRS.

Substitute your forwarder_endpoint in the following example.

Starting with environment variables and optional arguments:
 
export CRS_TAGS={tags}
export AZ_CRS_ARGUMENTS=enable,api.url={forwarder_endpoint},log=debug,delayTermination=120000,delayInitiation=0
java MyApp

Properties File

A third way to set the CRS parameters is to use a local .properties file. There are two default locations where CRS looks for the properties file, and you can specify a custom properties file as a command line argument. CRS looks for the properties file in the following order:

  1. the file provided via the -XX:AzCRSArguments=props=/path/to/config.properties argument

  2. ~/.az_crs/config.properties in the user’s home directory

  3. $JRE/lib/crs.properties, where $JRE is the directory where the JRE is located