SIMATIC WinCC Open Architecture Forum

Hello!
I have a problem with DIST between one of our system, when i start DIST manager on system SMT1273A, the DIST buffer starts to increase. It can increase from SVV27A to SMT1273A or from SVV27A to SMT1273B. The dispatch shows a big pending send traffic:

WCCILdist1:WCCILdist (3.15 platform Windows AMD64 linked at Apr 27 2020 13:34:58 (7305a40410a)) [2021.03.11;11:19:38:260 ] status report:
WCCILdist1:PID: 30404 StartTime: "2020.12.01 16:11:55.122"
WCCILdist1:Managerstate : STATE_RUNNING
WCCILdist1:-- Manager connection status:
WCCILdist1: *: Target is active, #: Accepting messages, C: Connecting, x: Closing, X: Disconnected
WCCILdist1:*# (SYS: 27 Dist -num 1 CONN: 1) @ SVV27A:57707 (::1) --> (SYS: 27 Data -num 0 CONN: 1) @ SVV27A:4897 (::1) : Msg. Comp: none Recv (pending / max pending / total): 0B / 64kB / 857MB Send (pending / max pending / total): 0B / 6kB / 6kB
WCCILdist1:*# (SYS: 27 Dist -num 1 CONN: 1) @ SVV27A:57711 (::1) --> (SYS: 27 Event -num 0 CONN: 1) @ SVV27A:4998 (::1) : Msg. Comp: none Recv (pending / max pending / total): 11kB / 64kB / 2829MB Send (pending / max pending / total): 276B / 34MB / 1724628MB
WWCCILdist1:*# (SYS: 27 Dist -num 1 CONN: 1) @ SVV27A:4777 (::ffff:X.X.X.X) --> (SYS: 1273 Dist -num 1 CONN: 2) @ SMT1273B:50760 (::ffff:X.X.X.X) : Msg. Comp: none Recv (pending / max pending / total): 324B / 64kB / 2678MB Send (pending / max pending / total): 152MB / 755MB / 5157592MB Alive status: Connected timeout: 2021.03.11;11:19:48:250
WCCILdist1: (SYS: 27 Dist -num 1 CONN: 1) @ SVV27A:4777 (::ffff:X.X.X.X) --> (SYS: 1273 Dist -num 1 CONN: 1) @ SMT1273A:50458 (::ffff:X.X.X.X) : Msg. Comp: none Recv (pending / max pending / total): 0B / 64kB / 13MB Send (pending / max pending / total): 278kB / 36MB / 1015MB Alive status: Connected timeout: 2021.03.11;11:22:56:905

How can i find out the reason of such a big pending traffic? Pings are fine, wireshark doesnt show any troubles.
3.15 P027

If you want to know if it is a problem that is in this moment a big amount of data in the buffer you have to check if the value decreases or increases and how long it takes to process data.
Possibly it is just a peak in the message traffic, e.g. sending the DP identification, and therefore you see this information.

Best Regards
Leopold Knipp
Senior Support Specialist

Thanks!
In that case the pending traffic is constantly increasing. It starts to decrease only if i switch off the DIST manager on SMT1273A (which is redu with SMT1273B). After turning off, the pending traffic falls to 0 MB within one minute.
I'd like to know what can i do for finding out the reasons of this behaviour?

As the analysis will need to share some data please get in contact with your common WinCC OA support.
Why is the Dist Manager stopped in one server?

Best Regards
Leopold Knipp
Senior Support Specialist