Currently, `TransportGetShutdownStatusAction` is executed in a transport thread, this action can do a substantial amount of work (O(# shards) in some cases) in the transport thread preventing pending transport tasks to make progress and potentially causing cluster instability. This action should be dispatched into a different thread pool to avoid such issues.
x-pack/plugin/shutdown/src/main/java/org/elasticsearch/xpack/shutdown/TransportGetShutdownStatusAction.java
response = new GetShutdownStatusAction.Response(new ArrayList<>());
        } else if (request.getNodeIds().length == 0) {
            final List<SingleNodeShutdownStatus> shutdownStatuses = nodesShutdownMetadata.getAll()
                .values()
                .stream()
                .map(
                    ns -> new SingleNodeShutdownStatus(
                        ns,
                        shardMigrationStatus(
                            state,
                            ns.getNodeId(),
                            ns.getType(),
                            ns.getNodeSeen(),
                            clusterInfoService,
                            snapshotsInfoService,
                            allocationService,
                            allocationDeciders
                        ),
                        new ShutdownPersistentTasksStatus(),
                        new ShutdownPluginsStatus(pluginShutdownService.readyToShutdown(ns.getNodeId(), ns.getType()))
                    )
                )
                .collect(Collectors.toList());
            response = new GetShutdownStatusAction.Response(shutdownStatuses);
        } else {
            new ArrayList<>();
            final List<SingleNodeShutdownStatus> shutdownStatuses = Arrays.stream(request.getNodeIds())
                .map(nodesShutdownMetadata::get)
                .filter(Objects::nonNull)
                .map(