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
| Issue | Resolution |
|---|---|
| Redis Gears fails to load after upgrade | Verify required runtimes (Python/JVM) are installed on all nodes. |
| Module load errors referencing missing libraries | Run ldd on module files and resolve any "not found" dependencies. |
| Gears execute inconsistently across nodes | Ensure identical dependency paths and versions across all nodes. |
| Python gears fail at runtime | Install the required Python runtime and packages on every node. |
| JVM gears fail to initialize | Ensure a JRE/JDK is installed and correctly referenced. |
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.soLook 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
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
lddto 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
lddon module filesRedis logs
Redis Gears version and deployment details
0 comments
Please sign in to leave a comment.