Redis Gears Fails After Upgrade Due to Missing Dependencies

Redis Gears relies on external runtimes (Python or JVM) and shared libraries that are not always bundled with the module, and after a Redis Enterprise cluster upgrade, these dependencies may no longer be present or correctly linked on all nodes. This commonly results in Redis Gears failing to load or execute. This article explains how to identify required dependencies, validate what is missing, and correctly stage them across all nodes using Step-by-Step Instructions and Troubleshooting.

Quick Fix Table

Prerequisites

Access and permissions

• SSH access to all Redis Enterprise cluster nodes

• Permission to read/write system directories and install dependencies

Cluster awareness

• Identify which Redis Gears engines are in use:

  • Python

  • JVM

• Access to Redis Gears module files on each node

Common Causes

Missing runtime dependencies after upgrade

• Python or JVM runtimes not present on new or upgraded nodes

Shared libraries not found

• Required .so dependencies missing or not in library path

Inconsistent environments across nodes

• Different versions or paths cause module load failures

Application-level dependencies missing

• Python packages or Java dependencies not staged

Step-by-Step: Identify Required Dependencies

Check Redis Gears engine usage

Determine whether you are using:

• Python engine

• JVM engine

• Both

Inspect module dependencies using ldd

Run on each node:

ldd /path/to/redisgears.so
ldd /path/to/gears_python.so
ldd /path/to/gears_jvm.so

Look for:

• not found entries → must be resolved

Verify runtime versions

Python engine

• Confirm supported Python version from Redis Gears release notes

• Verify presence of:

  • Python runtime

  • libpython3.x.so

JVM engine

• Confirm compatible JRE/JDK version

• Verify:

  • libjvm.so

  • JAVA_HOME or module configuration

4. Inventory application dependencies

Python

• Use:

  pip freeze

• Ensure all packages are available for target OS/architecture

Native extensions

• Confirm compatibility with node OS and architecture

Step-by-Step: Stage Dependencies Across Nodes

Copy required runtimes and libraries

• Python runtime + libraries

• JRE/JDK (if applicable)

• Required shared libraries

Place dependencies in consistent paths

• Use identical directory structure on all nodes

• Example:

  • /opt/redislabs/gears-deps/

Configure library paths

If not using system paths:

• Option 1: Add to system library path:

  • /usr/lib, /usr/lib64, /lib64

  • Run:

    ldconfig

• Option 2: Use absolute paths in module configuration

  • Currently vague, possibly unsupported as a generic instruction.

  • Fix: either delete or replace with specific, documented configuration options or environment variables, if they exist.

• Set correct permissions

• Directories: 0755

• Files: 0644

• Binaries: 0755

Ensure Redis processes can read and execute all dependencies

Validate consistency across nodes

• Same:

  • Paths

  • Versions

  • File structure

Important

• Mismatched environments are a leading cause of failures

Step-by-Step: Validate Redis Gears After Fix

Reload or restart module (if required)

• Must be removed or turned into finalized instructions. For example:

  • “If Redis Gears did not automatically reload after fixing dependencies, restart the database or reload the module using rladmin or the UI as per Redis Enterprise documentation.”

Verify module status

• Confirm Redis Gears loads successfully

Run test gear

• Execute a known working script

• Confirm expected behavior

Troubleshooting

Module fails to load

• Check logs for missing .so dependencies

• Re-run ldd to confirm all libraries resolved

Python gears fail at runtime

• Missing Python packages

• Incorrect Python version

JVM gears fail

• JAVA_HOME not set

• JRE/JDK missing or incompatible

Works on some nodes but not others

• Environment inconsistency across nodes

Permissions errors

• Ensure Redis user can access all files

Guardrails and Best Practices

Always keep environments identical

• Same dependency versions and paths on all nodes

Avoid partial upgrades

• Ensure all nodes are updated before validating

Validate before production rollout

• Test in staging with identical setup

Do not rely on implicit system libraries

• Explicitly validate all dependencies with ldd

When You May Not Need These Dependencies

If not using Python or JVM engines

• You do not need to install those runtimes

Important

• Most Redis Gears deployments use Python

• Confirm before skipping

When to Contact Support

Engage Redis Support if:

• Dependencies are correctly installed but module still fails

• Inconsistent behavior persists across nodes

• You cannot identify missing libraries

Provide:

• Output of ldd on module files

• Redis logs

• Redis Gears version and deployment details