Minor refactor in start script to remove Kafka-related leftovers

[danielgospodinow]

What

CC's start script defines variables with a KAFKA_ prefix which is incorrect. This is likely a leftover from copy-pasting Kafka start scripts. 😁

Looking at kafka-run-class.sh and kafka-server-start.sh further supports my claim. Lol.

Why

Might cause a confusion when reading the code, especially to an engineer that's new to the codebase.

Categorization

• documentation
• bugfix
• new feature
• refactor
• security/CVE
• other

[danielgospodinow]

This is the only line I've removed given that kafka.logs.dir is not part of Cruise Control. Everything else is just renaming.

[kyguy]

+1

[kyguy]

CircleCI failures are unrelated to the changes in this PR, they are due to some flaky tests which should be resolved by #2338.

[mimaison]

This is a major operational change for anyone using Cruise Control. I expect a (large?) portion of users set some of these environment variables to tune Cruise Control and this is going to break their environments.

I can understand the desire to move away from Kafka names but it should be done in a compatible manner to give time for people to migrate.

I also wonder if names prefixed with something like CC_ would be better than the names used i this PR.

[danielgospodinow]

I expect a (large?) portion of users set some of these environment variables to tune Cruise Control and this is going to break their environments.

True. Yet I think it's the right thing to do since the current names are confusing if you operate both CC and Kafka (which obviously is quite common), and it's anyway a simple change to adopt if something breaks.

I also wonder if names prefixed with something like CC_ would be better than the names used i this PR.

Sure, I'm fine with this suggestion too.

[Copilot]

Pull request overview

This PR refactors kafka-cruise-control-start.sh to remove Kafka-prefixed environment variables (KAFKA_*) that were likely copy/pasted leftovers, making the script’s configuration surface less confusing for Cruise Control users.

Changes:

• Renames several KAFKA_* env vars (e.g., KAFKA_OPTS, KAFKA_HEAP_OPTS, KAFKA_JMX_OPTS) to more generic equivalents (JVM_OPTS, HEAP_OPTS, JMX_OPTS, etc.).
• Updates the Java launch command to use the renamed variables.
• Removes some Kafka-specific log option wiring.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Suppressed comments (5)

kafka-cruise-control-start.sh:109

• This debug toggle still checks DEBUG. If you switch to a CC-specific variable name (e.g., CRUISE_CONTROL_DEBUG) to avoid collisions with common DEBUG env vars, this condition should be updated accordingly.

# Set Debug options if enabled
if [ "x$DEBUG" != "x" ]; then

kafka-cruise-control-start.sh:71

• Using a generic DEBUG env var is likely to cause unintended Java debug enablement (many environments set DEBUG for unrelated tooling). Consider switching to a CC-specific name (e.g., CRUISE_CONTROL_DEBUG) and only mapping from the deprecated KAFKA_DEBUG for backward compatibility.

This issue also appears on line 107 of the same file.

# Backward compatibility for deprecated KAFKA_* env vars (remove after migration)
: "${JMX_OPTS:=${KAFKA_JMX_OPTS:-}}"
: "${LOG4J_OPTS:=${KAFKA_LOG4J_OPTS:-}}"
: "${JVM_OPTS:=${KAFKA_OPTS:-}}"
: "${HEAP_OPTS:=${KAFKA_HEAP_OPTS:-}}"
: "${JVM_PERFORMANCE_OPTS:=${KAFKA_JVM_PERFORMANCE_OPTS:-}}"
: "${GC_LOG_OPTS:=${KAFKA_GC_LOG_OPTS:-}}"
: "${DEBUG:=${KAFKA_DEBUG:-}}"

kafka-cruise-control-start.sh:86

• The Cygwin LOG_DIR path conversion was removed. LOG_DIR is still used to build JVM args (e.g., -Xloggc:$LOG_DIR/...), so on Cygwin this can regress if Java expects Windows-style paths. Consider restoring the conversion independent of any Kafka-specific -Dkafka.logs.dir flag.

# Log directory to use
if [ "x$LOG_DIR" = "x" ]; then
  LOG_DIR="$base_dir/logs"
fi

kafka-cruise-control-start.sh:81

• if [ $JMX_PORT ]; then will emit a test error when JMX_PORT is unset/empty. Use a proper non-empty check and quote the variable to avoid noisy stderr output and edge-case parsing issues.

# JMX port to use
if [  $JMX_PORT ]; then
  JMX_OPTS="$JMX_OPTS -Dcom.sun.management.jmxremote.port=$JMX_PORT "
fi

kafka-cruise-control-start.sh:148

• The -f test should quote the path to avoid word-splitting/globbing issues (e.g., if base_dir contains spaces).

#Add jaas file to JVM_OPTS if present
if [ -f $base_dir/config/cruise_control_jaas.conf ]
then
  JVM_OPTS="-Djava.security.auth.login.config=$base_dir/config/cruise_control_jaas.conf $JVM_OPTS"
fi