Rename the bulk thread pool to write thread pool (#29593)

This commit renames the bulk thread pool to the write thread pool. This
is to better reflect the fact that the underlying thread pool is used to
execute any document write request (single-document index/delete/update
requests, and bulk requests).

With this change, we add support for fallback settings
thread_pool.bulk.* which will be supported until 7.0.0.

We also add a system property so that the display name of the thread
pool remains as "bulk" if needed to avoid breaking users.

Author: jasontedor

docs/reference/cat.asciidoc

@@ -93,8 +93,8 @@ Responds with:
 // TESTRESPONSE[s/9300 27 sLBaIGK/\\d+ \\d+ .+/ _cat]
 
 You can also request multiple columns using simple wildcards like
-`/_cat/thread_pool?h=ip,bulk.*` to get all headers (or aliases) starting
-with `bulk.`.
+`/_cat/thread_pool?h=ip,queue*` to get all headers (or aliases) starting
+with `queue`.
 
 [float]
 [[numeric-formats]]

docs/reference/cat/thread_pool.asciidoc

@@ -15,7 +15,6 @@ Which looks like:
 [source,txt]
 --------------------------------------------------
 node-0 analyze             0 0 0
-node-0 bulk                0 0 0
 node-0 fetch_shard_started 0 0 0
 node-0 fetch_shard_store   0 0 0
 node-0 flush               0 0 0
@@ -28,6 +27,7 @@ node-0 refresh             0 0 0
 node-0 search              0 0 0
 node-0 snapshot            0 0 0
 node-0 warmer              0 0 0
+node-0 write               0 0 0
 --------------------------------------------------
 // TESTRESPONSE[s/\d+/\\d+/ _cat]
 
@@ -44,7 +44,6 @@ The second column is the thread pool name
 --------------------------------------------------
 name
 analyze
-bulk
 fetch_shard_started
 fetch_shard_store
 flush
@@ -57,6 +56,7 @@ refresh
 search
 snapshot
 warmer
+write
 --------------------------------------------------
 
 

docs/reference/modules/threadpool.asciidoc

@@ -27,11 +27,10 @@ There are several thread pools, but the important ones include:
 `analyze`::
     For analyze requests. Thread pool type is `fixed` with a size of 1, queue size of 16.
 
-`bulk`::
-    For bulk operations. Thread pool type is `fixed`
-    with a size of `# of available processors`,
-    queue_size of `200`.  The maximum size for this pool
-    is `1 + # of available processors`.
+`write`::
+    For single-document index/delete/update and bulk requests. Thread pool type
+    is `fixed` with a size of `# of available processors`, queue_size of `200`.
+    The maximum size for this pool is `1 + # of available processors`.
 
 `snapshot`::
     For snapshot/restore operations. Thread pool type is `scaling` with a

modules/reindex/src/test/java/org/elasticsearch/index/reindex/RetryTests.java

@@ -158,10 +158,10 @@ private void testCase(
 
         final Settings nodeSettings = Settings.builder()
                 // use pools of size 1 so we can block them
-                .put("thread_pool.bulk.size", 1)
+                .put("thread_pool.write.size", 1)
                 .put("thread_pool.search.size", 1)
                 // use queues of size 1 because size 0 is broken and because search requests need the queue to function
-                .put("thread_pool.bulk.queue_size", 1)
+                .put("thread_pool.write.queue_size", 1)
                 .put("thread_pool.search.queue_size", 1)
                 .put("node.attr.color", "blue")
                 .build();
@@ -203,7 +203,7 @@ private void testCase(
             assertBusy(() -> assertThat(taskStatus(action).getSearchRetries(), greaterThan(0L)));
 
             logger.info("Blocking bulk and unblocking search so we start to get bulk rejections");
-            CyclicBarrier bulkBlock = blockExecutor(ThreadPool.Names.BULK, node);
+            CyclicBarrier bulkBlock = blockExecutor(ThreadPool.Names.WRITE, node);
             initialSearchBlock.await();
 
             logger.info("Waiting for bulk rejections");

rest-api-spec/src/main/resources/rest-api-spec/test/cat.thread_pool/10_basic.yml

@@ -1,6 +1,5 @@
 ---
 "Test cat thread_pool output":
-
   - skip:
         version: " - 6.99.99"
         reason: this API was changed in a backwards-incompatible fashion in 7.0.0 so we need to skip in a mixed cluster
@@ -33,29 +32,29 @@
 
   - do:
       cat.thread_pool:
-          thread_pool_patterns: bulk,management,flush,generic,force_merge
+          thread_pool_patterns: write,management,flush,generic,force_merge
           h: id,name,active
           v: true
 
   - match:
       $body: |
                /^  id \s+ name        \s+ active \n
-                  (\S+\s+ bulk        \s+ \d+    \n
-                   \S+\s+ flush       \s+ \d+    \n
+                  (\S+\s+ flush       \s+ \d+    \n
                    \S+\s+ force_merge \s+ \d+    \n
                    \S+\s+ generic     \s+ \d+    \n
-                   \S+\s+ management  \s+ \d+    \n)+  $/
+                   \S+\s+ management  \s+ \d+    \n
+                   \S+\s+ write       \s+ \d+    \n)+  $/
 
   - do:
       cat.thread_pool:
-          thread_pool_patterns: bulk
-          h: id,name,type,active,pool_size,queue,queue_size,rejected,largest,completed,core,max,size,keep_alive
+          thread_pool_patterns: write
+          h: id,name,type,active,size,queue,queue_size,rejected,largest,completed,min,max,keep_alive
           v: true
 
   - match:
       $body: |
-               /^  id  \s+ name \s+ type  \s+ active \s+ pool_size \s+ queue \s+ queue_size \s+ rejected \s+ largest \s+ completed \s+ core \s+ max \s+ size \s+ keep_alive \n
-                  (\S+ \s+ bulk \s+ fixed \s+ \d+    \s+ \d+       \s+ \d+   \s+ (-1|\d+)   \s+ \d+      \s+ \d+     \s+ \d+       \s+ \d*  \s+ \d* \s+ \d*  \s+ \S*        \n)+  $/
+               /^  id  \s+ name  \s+ type  \s+ active \s+ size \s+ queue \s+ queue_size \s+ rejected \s+ largest \s+ completed \s+ max \s+ keep_alive \n
+                  (\S+ \s+ write \s+ fixed \s+ \d+    \s+ \d+  \s+ \d+   \s+ (-1|\d+)   \s+ \d+      \s+ \d+     \s+ \d+       \s+ \d* \s+ \S*        \n)+  $/
 
   - do:
       cat.thread_pool:
@@ -71,11 +70,11 @@
 
   - do:
       cat.thread_pool:
-          thread_pool_patterns: bulk,search
+          thread_pool_patterns: write,search
           size: ""
 
   - match:
       $body: |
                /  #node_name     name       active     queue     rejected
-               ^  (\S+       \s+ bulk   \s+ \d+    \s+ \d+   \s+ \d+      \n
-                   \S+       \s+ search \s+ \d+    \s+ \d+   \s+ \d+      \n)+  $/
+               ^  (\S+       \s+ search  \s+ \d+    \s+ \d+   \s+ \d+      \n
+                   \S+       \s+ write   \s+ \d+    \s+ \d+   \s+ \d+      \n)+  $/

server/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -83,7 +83,7 @@ public TransportShardBulkAction(Settings settings, TransportService transportSer
                                     MappingUpdatedAction mappingUpdatedAction, UpdateHelper updateHelper, ActionFilters actionFilters,
                                     IndexNameExpressionResolver indexNameExpressionResolver) {
         super(settings, ACTION_NAME, transportService, clusterService, indicesService, threadPool, shardStateAction, actionFilters,
-            indexNameExpressionResolver, BulkShardRequest::new, BulkShardRequest::new, ThreadPool.Names.BULK);
+            indexNameExpressionResolver, BulkShardRequest::new, BulkShardRequest::new, ThreadPool.Names.WRITE);
         this.updateHelper = updateHelper;
         this.mappingUpdatedAction = mappingUpdatedAction;
     }

server/src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java

@@ -46,7 +46,7 @@ public TransportDeleteAction(Settings settings, TransportService transportServic
                                  ActionFilters actionFilters, IndexNameExpressionResolver indexNameExpressionResolver,
                                  TransportBulkAction bulkAction, TransportShardBulkAction shardBulkAction) {
         super(settings, DeleteAction.NAME, transportService, clusterService, indicesService, threadPool, shardStateAction,
-            actionFilters, indexNameExpressionResolver, DeleteRequest::new, DeleteRequest::new, ThreadPool.Names.BULK,
+            actionFilters, indexNameExpressionResolver, DeleteRequest::new, DeleteRequest::new, ThreadPool.Names.WRITE,
             bulkAction, shardBulkAction);
     }
 

server/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java

@@ -54,7 +54,7 @@ public TransportIndexAction(Settings settings, TransportService transportService
                                 ActionFilters actionFilters, IndexNameExpressionResolver indexNameExpressionResolver,
                                 TransportBulkAction bulkAction, TransportShardBulkAction shardBulkAction) {
         super(settings, IndexAction.NAME, transportService, clusterService, indicesService, threadPool, shardStateAction,
-            actionFilters, indexNameExpressionResolver, IndexRequest::new, IndexRequest::new, ThreadPool.Names.BULK,
+            actionFilters, indexNameExpressionResolver, IndexRequest::new, IndexRequest::new, ThreadPool.Names.WRITE,
             bulkAction, shardBulkAction);
     }
 

server/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java

@@ -60,7 +60,7 @@ public TransportResyncReplicationAction(Settings settings, TransportService tran
                                             ShardStateAction shardStateAction, ActionFilters actionFilters,
                                             IndexNameExpressionResolver indexNameExpressionResolver) {
         super(settings, ACTION_NAME, transportService, clusterService, indicesService, threadPool, shardStateAction, actionFilters,
-            indexNameExpressionResolver, ResyncReplicationRequest::new, ResyncReplicationRequest::new, ThreadPool.Names.BULK);
+            indexNameExpressionResolver, ResyncReplicationRequest::new, ResyncReplicationRequest::new, ThreadPool.Names.WRITE);
     }
 
     @Override

server/src/main/java/org/elasticsearch/action/update/TransportUpdateAction.java

@@ -86,7 +86,7 @@ public TransportUpdateAction(Settings settings, ThreadPool threadPool, ClusterSe
 
     @Override
     protected String executor() {
-        return ThreadPool.Names.BULK;
+        return ThreadPool.Names.WRITE;
     }
 
     @Override