The api/perf Resource

The api/perf resource reports the performance statistics described below.

For an overview see page eXtremeDB Web Service Resources

In order to enable access to eXtremeDB performance statistics the performance monitor must be enabled and the REST server must be started. When using xSQL to start the REST server, the performance monitor is explicitly enabled in the configuration file. For example:

     
    database_name : xsqldb,
    database_size : 100m, 
     
    perfmon : {
        database_size : 64m
    },
     
    rest : {
        addr : 127.0.0.1,
        port : 8083
    }
     

Note that, for the perf resource, the perfmon section must be included in the xSQL configuration file. (See page xSQL Web Services REST Parameters for further information).

With perfmon enabled, and the REST server started with port 8083, the following http request will return a list of the available performance statistics:

 
    http://localhost:8083/api/perf
            
     

Performance statistics are of two types: counters and timings. The readings array displays the name, description and index number no for each counter and timing in the following format:

 
    {

    "databases":

    [
        {
    
            "name": "xsqldb",

            "no": 0
  
        }
    ],
    "nodes":
    [
    ],
    "readings":
    [
        {
            "name": "MCO_PERF_ERROR_COUNT",
            "description": "Error count",
            "type": "counter",
            "no": 0
        },
        ...
        {
            "name": "MCO_PERF_DB_CACHE_PAGES_WRITE_DELAYED",
            "description": "",
            "type": "counter",
            "no": 24
        },
        ...
        {
            "name": "MCO_PERF_DISK_READ_TIME",
            "description": "Disk read time",
            "type": "timing",
            "no": 100
        },
        ...
        {
            "name": "MCO_PERF_CLUSTER_NET_RECV_TIME",
            "description": "",
            "type": "timing",
            "no": 107
        }
    ]

    }
 

Individual counter values can be requested by specifying the index of the counter desired. (See the Request Parameters section below for further details.)

Counters

The following table lists the available counters:

Index No	Name	Description
0	MCO_PERF_ERROR_COUNT	The error count
1	MCO_PERF_CONNECTION_COUNT	The current number of database connections
2	MCO_PERF_CONNECTS	The number of database connection requests
3	MCO_PERF_DISCONNECTS	The number of database disconnection requests
4	MCO_PERF_HOST_CPU_LOAD	The CPU load
5	MCO_PERF_HOST_MEMORY	The host memory usage
6	MCO_PERF_OPEN_TRANS_COUNT	The number of opened transactions
7	MCO_PERF_OPEN_CURSOR_COUNT	The number of cursors
8	MCO_PERF_LAST_SNAPSHOT_SIZE	The size of the last saved database snapshot
9	MCO_PERF_MAX_CONNECTIONS	The maximum number of database connections
10	MCO_PERF_DB_TOTAL_PAGES	The total number of memory pages
11	MCO_PERF_DB_FREE_PAGES	The number of free pages
12	MCO_PERF_DB_MEMORY	The number of used pages
13	MCO_PERF_DB_FILE_SIZE	The total database file size
14	MCO_PERF_DB_LOG_FILE_SIZE	The log file size
15	MCO_PERF_DB_USED_FILE_SIZE	The used database file size
16	MCO_PERF_DB_CACHE_HIT_COUNT	The disk cache hit count
17	MCO_PERF_DB_CACHE_MISS_COUNT	The disk cache miss count
18	MCO_PERF_DB_CACHE_PAGES_ALLOCATED	The total number of allocated cache pages
19	MCO_PERF_DB_CACHE_PAGES_USED	The number of cache pages used
20	MCO_PERF_DB_CACHE_PAGES_PINNED	The number of pinned (non-swappable) cache pages
21	MCO_PERF_DB_CACHE_PAGES_MODIFIED	The number of cache pages modified by active transactions
22	MCO_PERF_DB_CACHE_PAGES_DIRTY	The number of dirty cache pages
23	MCO_PERF_DB_CACHE_PAGES_COPIED	The number of copies of original pages
24	MCO_PERF_DB_CACHE_PAGES_WRITE_DELAYED	The number of write delayed pages

Timings

The following table lists the available timings:

Index No	Name	Description
100	MCO_PERF_DISK_READ_TIME	The disk read time
101	MCO_PERF_DISK_WRITE_TIME	The disk write time
102	MCO_PERF_LOG_WRITE_TIME	The log write time
103	MCO_PERF_COMMIT_TIME	The commit time
104	MCO_PERF_ROLLBACK_TIME_AVG	The rollback time
105	MCO_PERF_SNAPSHOT_DURATION	The snapshot duration
106	MCO_PERF_CLUSTER_NET_SEND_TIME	The cluster network data write time
107	MCO_PERF_CLUSTER_NET_RECV_TIME	The cluster network data read time

Request Parameters

The /api/perf/counters, /api/perf/timings requests show perf counter and timing readings. These resources support the following query parameters:

• db: database number.
• count: maximum number of readings to return.
• counter: index of the reading to get from the arrays; all readings if not set.
• node: node number.
• period: amount of time to return readings for, msec.
• since: timestamp to retrieve readings after.

The period and since parameters are mutually exclusive and cannot be used together. If none of the count, since or period parameters are specified, only the latest reading is returned.

The counter parameter corresponds to the no key in the reading descriptions above. The db parameter corresponds to the no key in the database description above.

The following snippet is an example of a counter reading for the request http://localhost:8083/api/perf/counters?db=0:

 
    {
        "now": 1514548579967,
        "counters":
        [
            {
                "stamp": 1514548579792,
                "db": 0,
                "node": 0,
                "values":
                [
                    0, 7, 0, 0, 0, 23, 0, 0, 0, 100, 406786, 406735, 3, 122880, 73940
                ]
            }
        ]
    }
     

The following snippet is an example of a timing reading for the request http://localhost:8083/api/perf/timings?db=0::

 
    {
        "now": 1514548622065,
        "timings":
        [
            {
                "stamp": 1514548621908,
                "db": 0,
                "node": 0,
                "values":
                {
                    "current":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ],
                    "min":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ],
                    "max":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ],
                    "avg":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ],
                    "total":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ],
                    "count":
                    [
                        0, 0, 0, 0, 0, 0, 0, 0
                    ]
                }
            }
        ]
    }