FIX 5.0 (or SP2) timeout on logins very occasional

Question

[Sometimes] I get very weird login issues. And it's only sometimes I keep getting disconnect and login and its a loop. Probably it could be due to server load while it is doing many things. I dont have a dedicated server for the DB or FIX and all services is put onto 1 machine. But when FIX doesnt work, it always due to login issue, and i suspect there is a timeout for it, such that if it cannot login to a FIX server for certain time (less than fractions of a second) i get the dreaded LOGOUT and attempt to login again by FIX and the loop goes forever until i actually reboot the computer or stop all services and application and run my FIX client first. Here is the log....

2022-07-08 18:00:55.055 +08:00 [INF] OMS QuickFix Service Started
2022-07-08 18:00:55.079 +08:00 [INF] Server Started - Accepting connections [0.0.0.0:7000]
2022-07-08 18:00:55.082 +08:00 [INF] OMS Fix Router Service Started: Version [1.08]
2022-07-08 18:00:55.083 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:00:55.139 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:00:57.071 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:00:57.076 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:00:59.080 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:00:59.085 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:01:01.091 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:01:01.096 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:01:03.103 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:01:03.107 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:01:05.126 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:01:05.130 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:01:07.135 +08:00 [INF] FIX Connection Succeeded.
2022-07-08 18:01:07.139 +08:00 [INF] Logout - FIXT.1.1:CLIENT1->EXECUTOR
2022-07-08 18:01:08.138 +08:00 [INF] OMS QuickFix Service Stopped

Once i see this log, i stop and and restart the application with many services shut down and it will work. Why is that, or is there a way for me the increase the connection timeout so it doesnt time out on me, is there an option or configuration in the FIX config (cfg) file that i can use to change this behavior? I am using FIX library QuickFixN, a C# .NET FIX library.

I really need to get this resolved, it just happens randomly and i dont know what the real problem is, what i stated above was theoretical.

Answer 1

OK, sorry, i think i figured it out. I have a WebApi service running at port 5000 (default) and once this service runs, it SOMEHOW (which i have no idea why and how) it also opens port 5001.

QuickFix by default runs on port 5001 and so that is why if my WebApi service ran first, my FIX application will NOT run. But if i run my FIX app first and then the WebApi, then everything works.

I just dont know why and how the WebApi will open 5001 as well for no reason when it's only suppose to run on port 5000 only. Strange.