No allocations remain in any zone - Common causes and quick fixes

No allocations remain in any zone – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.6-8.9

Briefly, this error occurs when Elasticsearch cannot allocate shards to any node in any zone due to lack of resources or improper configuration. This can be due to insufficient disk space, memory, or CPU resources. To resolve this issue, you can either add more nodes to your cluster, increase the resources of existing nodes, or adjust your shard allocation settings. Additionally, ensure that your nodes are properly configured and that there are no network connectivity issues.

This guide will help you check for common problems that cause the log ” no allocations remain in any zone ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “no allocations remain in any zone” classname is AllocationReducer.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

            List; Integer>> allocationsPerZoneInAscendingOrder = allocationsByZone.entrySet()
                .stream()
                .sorted(Map.Entry.comparingByValue())
                .toList();
            if (allocationsPerZoneInAscendingOrder.isEmpty()) {
                logger.warn("no allocations remain in any zone");
                throw new IllegalStateException("no allocations remain in any zone");
            }
            final List largestZone = allocationsPerZoneInAscendingOrder.get(allocationsPerZoneInAscendingOrder.size() - 1).getKey();
            final int largestZoneAllocations = allocationsPerZoneInAscendingOrder.get(allocationsPerZoneInAscendingOrder.size() - 1)
                .getValue();