Consensus Node Environment Variables

Overview

Solo lets you define environment variables for consensus nodes with an application.env file, passed through the --application-env flag. The consensus node start script loads this file when it launches the JVM, so every variable defined in it is visible to the Java process.

Variables that are only set on the node container, for example through custom Helm chart values, are not forwarded to the Java process. If you need a variable such as MALLOC_ARENA_MAX to be present in the running JVM environment, define it in application.env.

The application.env file

Write the variables as plain KEY=VALUE lines. Blank lines and lines starting with # are ignored:

# Limit glibc malloc arenas to reduce memory fragmentation.
MALLOC_ARENA_MAX=4
JAVA_OPTS=-XX:+UseG1GC -XX:MaxDirectMemorySize=128M

Pass the file to solo consensus network deploy:

solo consensus network deploy \
  --deployment "${SOLO_DEPLOYMENT}" \
  --application-env ./config/application.env

Solo stages your file as the application.env ConfigMap for the consensus nodes. The file replaces Solo’s default application.env content, so include every variable your nodes require.

Solo also sets the same variables on the node container, so the container environment and the JVM environment stay consistent without any extra configuration.

Verifying the JVM environment

To confirm a variable reached the running Java process, inspect the process environment inside the root container:

kubectl exec -n "${SOLO_NAMESPACE}" network-node1-0 -c root-container -- \
  sh -c 'tr "\0" "\n" < /proc/$(pgrep java)/environ | grep MALLOC_ARENA_MAX'

The command prints MALLOC_ARENA_MAX=4 when the variable is in effect and prints nothing when it is not.

Falcon values file

For One-shot Falcon deployments, put the same flag under the network section:

network:
  --application-env: './config/application.env'

For the complete list of Falcon network flags, see the Falcon Values File Reference.