Failed to read index file – How to solve related issues

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Failed to read index file – How to solve related issues

Opster Team

Jan-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you run 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 ” Failed to read index file ” 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: blobstore, discovery-file, index, repositories and repository-azure.

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 “Failed to read index file [{}]” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                     final BlobStoreIndexShardSnapshots shardSnapshots =
              ; Integer.toString(latest));
                    return new Tuple(shardSnapshots; latest);
                } catch (IOException e) {
                    final String file = SNAPSHOT_INDEX_PREFIX + latest;
                    logger.warn(() -> new ParameterizedMessage("failed to read index file [{}]"; file); e);
            } else if (blobKeys.isEmpty() == false) {
                logger.warn("Could not find a readable index-N file in a non-empty shard snapshot directory [{}]"; blobContainer.path());


Run the Check-Up to get a customized report like this:

Analyze your cluster