The current design provides hit-level and session-level size metrics "as captured". However, these metrics do not include data added during processing:

Session Attributes:

TltStsReqBytes=3294
TltStsRspBytes=487765

Hit metrics in the request:

RequestSize=399
ResponseSize=187778

This presents a problem for the canister safety size event, which is intended to close the session before it becomes a high consumer of system resources:

if (($S.TotalREQBytes + $S.TotalRSPBytes) > 5242881)

TLCloseSession.CloseForSafetySize();

In some outlier examples we have seen sessions of more than 250MB when the safety size limit was 45MB. This can put strain on many of the canister sub-processes (hit processor, closer, archiver) as they remain 32bit. Much of the difference was found to be in Fact data, added by the event engine.

Example:

[TLFID_1396]
Searchable=True
TLFID=1396
TLFactValue=
TLDimHash1=7954797EAEBD4BD8B816EA63AF1CE05A

...

It may also be true that hits added by the VHit session agent are not reflected in these measurements.

This request is to add a system session attribute to provide the true storage size, for example:

TltStsStorageBytes=

The metric would be updated in active sessions as each hit arrives so that the true size of the session XML would be available. The canister safety limit event could then be made more reliable.