Log Failing shard – How To Solve Related Issues


Log Failing shard – How To Solve Related Issues

Opster Team

Jan-20, Version: 1.7-8.0

 

Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues that cause many errors.

This guide will help you check for common problems that cause the log ” Failing shard ” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: allocation, cluster, routing and shard.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to pinpoint the cause of many errors and provides suitable actionable recommendations how to resolve them (free tool that requires no installation).

Log context

Log “Failing shard [{}]” classname is AllocationService.java
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                     failedShardEntry.getFailure(); failedAllocations + 1; currentNanoTime; System.currentTimeMillis(); false;
                    AllocationStatus.NO_ATTEMPT);
                if (failedShardEntry.markAsStale()) {
                    allocation.removeAllocationId(failedShard);
                }
                logger.warn(new ParameterizedMessage("failing shard [{}]"; failedShardEntry); failedShardEntry.getFailure());
                routingNodes.failShard(logger; failedShard; unassignedInfo; indexMetaData; allocation.changes());
            } else {
                logger.trace("{} shard routing failed in an earlier iteration (routing: {})"; shardToFail.shardId(); shardToFail);
            }
        }




 

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