log-analysis

This happens occasionally when shutting down the server:

Exception in thread "http-worker-15" java.lang.NullPointerException: null value in entry: exception=null
        at com.google.common.collect.CollectPreconditions.checkEntryNotNull(CollectPreconditions.java:32)
        at com.google.common.collect.ImmutableMap.entryOf(ImmutableMap.java:176)
        at com.google.common.collect.I

linux：HTTPConnectionPool(host='192.168.0.24', port=6801): Max retries exceeded with url: /listprojects.json (Caused by NewConnectionError('<requests.packages.urllib3.connection.HTTPConnection object at 0x7f0a78b2d828>: Failed to establish a new connection: [Errno 111] Connection refused',))
windows：HTTPConnectionPool(host='localhost', port=6801): Max retries exceeded with url: /jobs (Caused by Ne

Unlike all the existing charts that graph a string (most likely) against a number, this graphs numbers on both axises. So in addition to the configuration changes needed for passing the right field to chartjs, the PR for this should also change the "preferred type" to "number" for the x axis when the chart type is scatter plot.