[Samba] 4.17.1 rpcd_winreg, rpcd_spoolss and printing

[Jeremy Allison]

On Thu, Nov 03, 2022 at 04:08:28PM +0000, Tim ODriscoll via samba wrote:
>Dear All,
>
>I've made things a tiny bit better by reducing the log level to 1, so that the rpcd_winreg and rpcd_spoolss files don't grow by several Gb every day, and restarting sernet-samba-ad every couple of hours. People can mostly print after the restart, but quite soon the rpcd_winreg process starts to consume the server and it starts grinding to a halt.
>
>I'm still getting lots of rpcd_winreg processes hanging around consuming resources. I was hoping it was something todo with this:
>https://bugzilla.samba.org/show_bug.cgi?id=15201
>
>However, I'm running the latest sernet package 4.17.2.
>
>I'm a bit stuck as to know what to do next...
>
>I've tried building a new print server from scratch on Rocky 9, however that started to exhibit the same rpcd_winreg issue once I'd added a few printers to it, so I stopped as it was going to go the same way.
>
>Any pointers from anyone?.......
>
>Here's my 'top' output after I've restarted sernet-samba-ad, FWIW:
>top - 15:59:58 up 15 days,  6:59,  1 user,  load average: 16.92, 14.22, 11.98
>Tasks: 573 total,  28 running, 545 sleeping,   0 stopped,   0 zombie
>%Cpu(s): 78.8 us, 12.4 sy,  0.0 ni,  7.2 id,  0.3 wa,  0.0 hi,  1.3 si,  0.0 st
>KiB Mem : 32745508 total,  7403460 free, 11249884 used, 14092164 buff/cache
>KiB Swap: 33390588 total, 32957692 free,   432896 used. 19759024 avail Mem
>
>  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
>30204 root      20   0  799224  91776  18452 S  45.4  0.3  12:29.58 rpcd_winreg
>30206 root      20   0  791060  81660  18456 R  44.4  0.2   9:39.31 rpcd_winreg
>30205 root      20   0  794112  86668  18456 R  43.1  0.3  11:07.90 rpcd_winreg
>30207 root      20   0  783456  76004  18452 R  40.1  0.2   7:56.12 rpcd_winreg
>30208 root      20   0  777612  70172  18456 R  37.8  0.2   6:22.22 rpcd_winreg

Can you do an strace on an rpcd_winreg process ? That seems an inordinate
amount of CPU...