ODBC Request Monitoring and Cancellation

Request monitoring is supported for the ODBC app server. The following ODBC meters will be recorded for ODBC Requests:

Prior to this feature, the Modules database assigned to an ODBC server served no purpose. Now, a file named /default.api is looked for in the Modules root - whether that be the filesystem or a Modules database - and the configuration defined in that file is heeded to.

When a query comes in over ODBC, the odbcRowsSent and odbcBytesSent meters and their values are output in the ODBC app server request log, given that Request Monitoring is enabled in /default.api.

Request cancellation is now enabled for ODBC server as well. The /default.api will take in unsigned long values as limits for odbcRowsSent and odbcBytesSent. If the number of rows or bytes sent exceed the limits defined in /default.api, the sending of rows over the network ends prematurely and SQL-ODBCREQLIMIT is thrown. elapsedTime is also supported for cancellation, and XDMP-EXTIME is thrown if the time limit is exceeded. lockCount and readSize are not relevant for ODBC.

These values are purely e-node metrics and are not recorded on any d-nodes.

Configuration example:

With the following /default.api in the Modules root, a query will be canceled for one of these reasons:

• Run time exceeds 3 seconds.

• The number of bytes sent to the client exceeds 200000.

• The number of rows sent to the client exceeds 10000.

{
  "monitoring": {
   "general": { 
    "enabled": true
  },
 "limits" : {
 "elapsedTime" : 3,
    "odbcBytesSent": 200000,
    "odbcRowsSent": 10000
   }
  }
}