### Description

The health API response can become a few MBs (2-3MB if 50K indices are affected).

In less extreme situations the response can be in the 10s/100s of KB. 

It might be worthwhile looking into chunking its response (this might provide clients with a better experience too)
server/src/main/java/org/elasticsearch/health/Diagnosis.java
} else {
                builder.field(type.displayValue, values);
            }
            return builder;
        }
        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            Resource resource = (Resource) o;
            return type == resource.type && Objects.equals(values, resource.values) && Objects.equals(nodes, resource.nodes);
        }
        @Override
        public int hashCode() {
            return Objects.hash(type, values, nodes);
        }
        public Type getType() {
            return type;
        }
        @Nullable
        public Collection<String> getValues() {
            return values;
        }
        @Nullable
        public Collection<DiscoveryNode> getNodes() {
            return nodes;