Searching a large number of unavailable shards through e.g. the `*` pattern while a large cluster is recovering from a full restart or so, leads to extremely large responses containing an exception for each shard.


![](https://user-images.githubusercontent.com/6490959/193701098-868888bc-cdc7-4104-a32a-d9c84d74aef2.png)

This example shows a 375M on heap response for ~25k unavailable shards being returned. Over the wire, this serialises with a similar size and we'd have 700M+ peak heap usage for a search request when the valid search response in a green cluster might be much smaller than this.
It seems to me that we could mostly resolve this by not returning the stack trace in this specific case of the shard not available exception (it doesn't seem valuable for users and we made a similar fix around unavailable shards in snapshots state responses)? 
server/src/main/java/org/elasticsearch/action/search/AbstractSearchAsyncAction.java
* we can continue (cf. InitialSearchPhase#maybeFork).
         */
        if (shard == null) {
            assert assertExecuteOnStartThread();
            SearchShardTarget unassignedShard = new SearchShardTarget(null, shardIt.shardId(), shardIt.getClusterAlias());
            onShardFailure(shardIndex, unassignedShard, shardIt, new NoShardAvailableActionException(shardIt.shardId()));
        } else {
            final PendingExecutions pendingExecutions = throttleConcurrentRequests
                ? pendingExecutionsPerNode.computeIfAbsent(shard.getNodeId(), n -> new PendingExecutions(maxConcurrentRequestsPerNode))
                : null;
            Runnable r = () -> {
                final Thread thread = Thread.currentThread();
                try {
                    executePhaseOnShard(shardIt, shard, new SearchActionListener<Result>(shard, shardIndex) {
                        @Override
                        public void innerOnResponse(Result result) {
                            try {
                                onShardResult(result, shardIt);
                            } catch (Exception exc) {
                                onShardFailure(shardIndex, shard, shardIt, exc);
                            } finally {
                                executeNext(pendingExecutions, thread);
                            }
                        }
                        @Override
                        public void onFailure(Exception t) {
                            try {
                                onShardFailure(shardIndex, shard, shardIt, t);
                            } finally {
                                executeNext(pendingExecutions, thread);