Enum TodoQueue.DuplicationHandlingMode

Defines how duplicate todo submissions are handled by the queue. When a client sends a Todo into server, a server may accept the todo but client may not get the confirmation message, in which case client may re-submit the same todo (as identified by the SysID GDID) more than once. This leads to duplication of work and may be unacceptable for some applications (e.g. financial double-posting). Duplication detection will respond with OK acknowledgment for the Todo that have already been accepted.

Namespace: Azos.Sky.Workers.Server.Queue
Assembly: Azos.Sky.dll
Syntax
public enum DuplicationHandlingMode

Fields

Name Description
HostAccurateDetection

The server is going to check whether a Todo with the same SysID was already submitted and is in the queue. This detection mode is usually done in-store and provides the best host-level protection but takes more time to execute a store check request. This mode does not detect todos which have executed already and not in either queue or recent buffer
HostFastDetection

This is the default mode. The server is going to check whether a Todo with the same SysID was already submitted recently. The recency (time window size) is defined by the server configuration and is usually configured to represent a typical timeouts (60 sec = 3 typical 20 sec Glue calls) for re-submission. This detection mode is usually done in-RAM and provides the best balance between performance and protection guarantees. Note: this mode DOES NOT detect a case when this server was down and traffic was routed to a different server in a hostset. For more protection use HostsetDetection mode
HostsetDetection

The server will check itself then others in a host set for possible Todo resubmission. This mode provides the best protection at the expense of performance as cross-checking introduces extra network traffic.
NotDetected

The server is not checking for duplicate Todo instance submission. This is the fastest mode but leads to possible re-submission of the same Todo instance

Extension Methods