Web Services On Demand Limiters

This chapter contains the following topics:

Web Services On Demand Limiters

The Web Services interface resources of Oracle CRM On Demand can be shared by multiple organizations. Oracle CRM On Demand provides a limiting infrastructure to make sure that some users do not consume a disproportionate share of those resources. These limiters constrain customer organizations’ use of server-side resources to equitably share available resources among users and to minimize the possibility of denial-of-service incidents.

The following table summarizes the limiters, their default values, units, and error messages. For more information, contact Customer Care.

In addition to the limiters described in this appendix, there are a number of service allotments that promote the equitable use of resources. For more information, see About Service Allotments. Further information about the Web Services Request Rate limiter is provided in Web Services Request Rate.

Table Web Services On Demand Limiters

Limiter Name	Description	DefaultValue	Units	Error Message
Session limit quota	Maximum number of concurrent sessions for a company	10	sessions	Not applicable
Lifetime of Audit records	Maximum number of days Web services utilization records are saved. Records older than 30 days are purged.	30	days	Not applicable
Web Service Request Rate	Number of Web service messages that can be sent in one second	20	requests/second	The maximum rate of requests was exceeded. Please try again in {0} ms.
Web Service Request Size	Maximum size, in kilobytes, of a Web services request.	28800	KB	Request exceeded the size limit of {0} KB.
Web Service Session Inactivity Time Limit	How long, in seconds, that a Web services session can remain idle before being closed.	600	seconds	Internal Error: Session is not available. Aborting.
Maximum Records Returned	For return messages the maximum number of records returned for each query. A response never returns more than the specified number of records for a parent object in a request.	100 (fixed maximum value)	records	PageSize method argument cannot be greater than 100, specified by the server parameter ‘MaximumPageSize’.
Maximum Objects in a Web Services Request	The maximum number of objects that can be sent in a single SOAP request.	20 (fixed maximum value)	objects	Requests containing more than 20 objects are not allowed.

Web Services Request Rate

All integration requests (data exchange requests) in a session are subject to rate limiting. Rate limiting is implemented for the following reasons:

A user can perform long-running operations on the server that result in complex and long-running queries on the database.
A user can perform constant operations on the server that constantly use resources.

Rate limiting can alleviate the previous problems to some extent. Oracle CRM On Demand applies a restriction to each session to limit the number of requests for each second that clients can make. The rate limit is set to twenty requests for each second. This is measured as a minimum of 1/20th second wait time between requests.

If the rate limit is exceeded, the following error message is provided to subsequent SOAP requests:

The maximum rate of requests was exceeded. Please try again in <waitTime> ms.

There are two situations in which this error message is displayed:

Where the client sends more than 20 requests every second
Where the client sends requests at a rate faster than one request every 50 milliseconds.

For the second situation, a wait statement is recommended.