redis/redis-py · error · RedisClusterException

method script_load_for_pipeline() is not implemented

Error message

method script_load_for_pipeline() is not implemented

What it means

Raised by AbstractStrategy.script_load_for_pipeline() in redis/cluster.py:4126. This standalone-pipeline helper loads a Lua script and rewrites pipeline EVAL calls to EVALSHA for wire efficiency; it has no cluster implementation because scripts must be sharded across nodes and the cluster pipeline does not rewrite commands that way. Calling it directly on a cluster pipeline is unsupported.

Solutions

Drop the script_load_for_pipeline() call; the cluster pipeline routes EVAL/EVALSHA per-slot automatically.
Pre-load the script on all primaries manually with rc.cluster_execute_command('SCRIPT LOAD', script, target_nodes='primaries') if you want EVALSHA availability.
Use a non-cluster client if the standalone optimization is required.

Example fix

// before
pipe = rc.pipeline()
pipe.script_load_for_pipeline(script)
// after
pipe = rc.pipeline()
pipe.eval(script, numkeys, *keys)  # cluster handles routing

Defensive patterns

Strategy: validation

Validate before calling

from redis.cluster import RedisCluster
if not isinstance(rc, RedisCluster):
    pipe.script_load_for_pipeline(script)

Type guard

def supports_script_load_for_pipeline(client) -> bool:
    from redis.cluster import RedisCluster
    return not isinstance(client, RedisCluster)

Try / catch

from redis.exceptions import RedisClusterException
try:
    pipe.script_load_for_pipeline(script)
except RedisClusterException:
    pass

Prevention

Do not call standalone pipeline helpers on cluster pipelines.
Let EVAL/EVALSHA handle script loading in cluster mode.

When it happens

Trigger: Invoking pipe.script_load_for_pipeline(script) (or rc.script_load_for_pipeline(...)) on a RedisCluster or ClusterPipeline object, typically copied from standalone redis.Redis pipeline code.

Common situations: Migrating a standalone Redis pipeline optimization pattern to cluster mode; generic pipeline wrapper code that calls script_load_for_pipeline on every client type.

Related errors

AI-assisted analysis of redis/redis-py@6a6b581b48 (2026-08-10). Data as JSON: /api/errors/5b61482f4f23bff1. Report an issue: GitHub.

Appendix: source

Thrown at redis/cluster.py:4126

    @abstractmethod
    def reset(self):
        pass

    def exists(self, *keys):
        return self.execute_command("EXISTS", *keys)

    def eval(self):
        """ """
        raise RedisClusterException("method eval() is not implemented")

    def load_scripts(self):
        """ """
        raise RedisClusterException("method load_scripts() is not implemented")

    def script_load_for_pipeline(self, *args, **kwargs):
        """ """
        raise RedisClusterException(
            "method script_load_for_pipeline() is not implemented"
        )

    def annotate_exception(self, exception, number, command):
        """
        Provides extra context to the exception prior to it being handled
        """
        cmd = " ".join(map(safe_str, command))
        msg = (
            f"Command # {number} ({truncate_text(cmd)}) of pipeline "
            f"caused error: {exception.args[0]}"
        )
        exception.args = (msg,) + exception.args[1:]


class PipelineStrategy(AbstractStrategy):
    def __init__(self, pipe: ClusterPipeline):
        super().__init__(pipe)

View on GitHub (pinned to 6a6b581b48)