Version 0.8.61

- Implemented `max_jobs` feature (global maximum).

README.md

@@ -623,6 +623,14 @@ However, if you are trying to run Cronicle in an environment where WebSockets ar
 
 However, please only do this if you know exactly what you are doing, and why.
 
+### max_jobs
+
+You can optionally set a global maximum number of concurrent jobs to allow.  This is across all servers and categories, and is designed as an "emergency brake" for runaway events.  The property is called `max_jobs`.  The default is `0` (no limit).  Example:
+
+```js
+"max_jobs": 256
+```
+
 ## Storage Configuration
 
 The `Storage` object contains settings for the Cronicle storage system.  This is built on the [pixl-server-storage](https://www.npmjs.com/package/pixl-server-storage) module, which can write everything to local disk (the default), [Couchbase](http://www.couchbase.com/nosql-databases/couchbase-server) or [Amazon S3](https://aws.amazon.com/s3/).

lib/job.js

@@ -131,6 +131,11 @@ module.exports = Class.create({
 				}
 			}
 
+			var max_jobs = self.server.config.get('max_jobs') || 0;
+			if (max_jobs && (job_list.length >= max_jobs)) {
+				return callback( new Error("Global maximum of " + max_jobs + " " + Tools.pluralize("job", max_jobs) + " already running.") );
+			}
+
 			if (!category.enabled) {
 				return callback( new Error("Category '" + category.title + "' is disabled.") );
 			}

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "Cronicle",
-	"version": "0.8.60",
+	"version": "0.8.61",
 	"description": "A simple, distributed task scheduler and runner with a web based UI.",
 	"author": "Joseph Huckaby <[email protected]>",
 	"homepage": "https://github.com/jhuckaby/Cronicle",

sample_conf/config.json

@@ -25,6 +25,7 @@
 	"scheduler_startup_grace": 10,
 	"universal_web_hook": "",
 	"track_manual_jobs": false,
+	"max_jobs": 0,
 
 	"server_comm_use_hostnames": false,
 	"web_direct_connect": false,