From 6084acc8b6f0c427171f5074389654eb97a95149 Mon Sep 17 00:00:00 2001
From: Tim Sullivan <tsullivan@users.noreply.github.com>
Date: Wed, 24 Oct 2018 08:03:54 -0700
Subject: [PATCH] [Reporting] queue.pollEnabled setting adds ability to disable
 polling for idle jobs (#24295)

* [Reporting] New queue.pollEnabled setting adds ability to disable polling for idle jobs

* add an info log line

* note in docs
---
 docs/settings/reporting-settings.asciidoc        | 16 +++++++++++++++-
 x-pack/plugins/reporting/index.js                |  1 +
 .../plugins/reporting/server/lib/create_queue.js | 16 ++++++++++++++--
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/docs/settings/reporting-settings.asciidoc b/docs/settings/reporting-settings.asciidoc
index c6463a5bf257..6aafeedf9cba 100644
--- a/docs/settings/reporting-settings.asciidoc
+++ b/docs/settings/reporting-settings.asciidoc
@@ -51,8 +51,22 @@ reports, you might need to change the following settings.
 How often the index that stores reporting jobs rolls over to a new index.
 Valid values are `year`, `month`, `week`, `day`, and `hour`. Defaults to `week`.
 
+`xpack.reporting.queue.pollEnabled`::
+Set to `true` (default) to enable the Kibana instance to to poll the index for
+pending jobs and claim them for execution. Setting this to `false` allows the
+Kibana instance to only add new jobs to the reporting queue, list jobs, and
+provide the downloads to completed report through the UI.
+
+[NOTE]
+============
+Running multiple instances of Kibana in a cluster for load balancing of
+reporting requires identical values for `xpack.reporting.encryptionKey` and, if
+security is enabled, `xpack.security.encryptionKey`.
+============
+
 `xpack.reporting.queue.pollInterval`::
-How often idle workers poll the index for pending jobs. Defaults to `3000` (3 seconds).
+Specifies the number of milliseconds that idle workers wait between polling the
+index for pending jobs. Defaults to `3000` (3 seconds).
 
 [[xpack-reporting-q-timeout]]`xpack.reporting.queue.timeout`::
 How long each worker has to produce a report. If your machine is slow or under
diff --git a/x-pack/plugins/reporting/index.js b/x-pack/plugins/reporting/index.js
index ee1514e9bf92..50c4371e92f2 100644
--- a/x-pack/plugins/reporting/index.js
+++ b/x-pack/plugins/reporting/index.js
@@ -71,6 +71,7 @@ export const reporting = (kibana) => {
         }).default(),
         queue: Joi.object({
           indexInterval: Joi.string().default('week'),
+          pollEnabled: Joi.boolean().default(true),
           pollInterval: Joi.number().integer().default(3000),
           pollIntervalErrorMultiplier: Joi.number().integer().default(10),
           timeout: Joi.number().integer().default(120000),
diff --git a/x-pack/plugins/reporting/server/lib/create_queue.js b/x-pack/plugins/reporting/server/lib/create_queue.js
index 7d221149b9b5..c09220a52c23 100644
--- a/x-pack/plugins/reporting/server/lib/create_queue.js
+++ b/x-pack/plugins/reporting/server/lib/create_queue.js
@@ -18,18 +18,30 @@ function createQueueFn(server) {
   const createWorkers = createWorkersFactory(server);
   const { getClient } = server.plugins.elasticsearch.getCluster('admin');
 
+  const logger = createTaggedLogger(server, ['reporting', 'esqueue']);
   const queueOptions = {
     doctype: QUEUE_DOCTYPE,
     interval: queueConfig.indexInterval,
     timeout: queueConfig.timeout,
     dateSeparator: dateSeparator,
     client: getClient(),
-    logger: createTaggedLogger(server, ['reporting', 'esqueue'])
+    logger,
   };
 
   const queue = new Esqueue(index, queueOptions);
 
-  createWorkers(queue);
+  if (queueConfig.pollEnabled) {
+    // create workers to poll the index for idle jobs waiting to be claimed and executed
+    createWorkers(queue);
+  } else {
+    logger(
+      'xpack.reporting.queue.pollEnabled is set to false. This Kibana instance ' +
+      'will not poll for idle jobs to claim and execute. Make sure another ' +
+      'Kibana instance with polling enabled is running in this cluster so ' +
+      'reporting jobs can complete.',
+      ['info']
+    );
+  }
 
   return queue;
 }