we have an customer who are now using lustre-1.8.3.ddn3.3.
A single user on single client writes many files (100K files, file size average 600KB) and read them by same user on same client.
When that user read thease files, he can't read some files and returned "no such or directry". Howerver, if same user reads these files on other clients, he can read them.

There are following error messages on MDS when the problem happened.
Nov 3 06:08:19 md1 kernel: LustreError: 9406:0:(upcall_cache.c:342:upcall_cache_get_entry()) acquire timeout exceeded for key 1104

could you pleaes have a look at the log files and find out whether this is known issue on 1.8.3 or not?

Thanks