Failed to flush shard post recovery – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 1.7-1.7

Briefly, this error occurs when Elasticsearch is unable to flush a shard after recovery. This could be due to insufficient disk space, network issues, or a corrupted index. To resolve this, you can try freeing up disk space, checking your network connection, or repairing the corrupted index. If the problem persists, consider reindexing your data or increasing the timeout settings.

This guide will help you check for common problems that cause the log ” failed to flush shard post recovery ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: flush, index, recovery and shard.

Log Context

Log “failed to flush shard post recovery” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                } catch (IllegalIndexShardStateException | FlushNotAllowedEngineException e) {
                    // we are being closed; or in created state; ignore
                    // OR; we are not allowed to perform flush; ignore
                } catch (Throwable e) {
                    logger.warn("failed to flush shard post recovery"; e);
            return left;
        } finally {