CURRENT slow and shaky network stability

Sat Apr 2 08:54:41 UTC 2016

Am Sat, 02 Apr 2016 01:07:55 -0700
Cy Schubert <Cy.Schubert at komquats.com> schrieb:

> In message <56F6C6B0.6010103 at protected-networks.net>, Michael Butler writes:
> > -current is not great for interactive use at all. The strategy of
> > pre-emptively dropping idle processes to swap is hurting .. big time.  
> 
> FreeBSD doesn't "preemptively" or arbitrarily push pages out to disk. LRU 
> doesn't do this.
> 
> > 
> > Compare inactive memory to swap in this example ..
> > 
> > 110 processes: 1 running, 108 sleeping, 1 zombie
> > CPU:  1.2% user,  0.0% nice,  4.3% system,  0.0% interrupt, 94.5% idle
> > Mem: 474M Active, 1609M Inact, 764M Wired, 281M Buf, 119M Free
> > Swap: 4096M Total, 917M Used, 3178M Free, 22% Inuse  
> 
> To analyze this you need to capture vmstat output. You'll see the free pool 
> dip below a threshold and pages go out to disk in response. If you have 
> daemons with small working sets, pages that are not part of the working 
> sets for daemons or applications will eventually be paged out. This is not 
> a bad thing. In your example above, the 281 MB of UFS buffers are more 
> active than the 917 MB paged out. If it's paged out and never used again, 
> then it doesn't hurt. However the 281 MB of buffers saves you I/O. The 
> inactive pages are part of your free pool that were active at one time but 
> now are not. They may be reclaimed and if they are, you've just saved more 
> I/O.
> 
> Top is a poor tool to analyze memory use. Vmstat is the better tool to help 
> understand memory use. Inactive memory isn't a bad thing per se. Monitor 
> page outs, scan rate and page reclaims.
> 
> 

I give up! Tried to check via ssh/vmstat what is going on. Last lines before broken pipe:

[...]
procs  memory       page                    disks     faults         cpu
r b w  avm   fre   flt  re  pi  po    fr   sr ad0 ad1   in    sy    cs us sy id
22 0 22 5.8G  1.0G 46319   0   0   0 55721 1297   0   4  219 23907  5400 95  5  0
22 0 22 5.4G  1.3G 51733   0   0   0 72436 1162   0   0  108 40869  3459 93  7  0
15 0 22  12G  1.2G 54400   0  27   0 52188 1160   0  42  148 52192  4366 91  9  0
14 0 22  12G  1.0G 44954   0  37   0 37550 1179   0  39  141 86209  4368 88 12  0
26 0 22  12G  1.1G 60258   0  81   0 69459 1119   0  27  123 779569 704359 87 13  0
29 3 22  13G  774M 50576   0  68   0 32204 1304   0   2  102 507337 484861 93  7  0
27 0 22  13G  937M 47477   0  48   0 59458 1264   3   2  112 68131 44407 95  5  0
36 0 22  13G  829M 83164   0   2   0 82575 1225   1   0  126 99366 38060 89 11  0
35 0 22 6.2G  1.1G 98803   0  13   0 121375 1217   2   8  112 99371  4999 85 15  0
34 0 22  13G  723M 54436   0  20   0 36952 1276   0  17  153 29142  4431 95  5  0
Fssh_packet_write_wait: Connection to 192.168.0.1 port 22: Broken pipe

This makes this crap system completely unusable. The server (FreeBSD 11.0-CURRENT #20
r297503: Sat Apr  2 09:02:41 CEST 2016 amd64) in question did poudriere bulk job. I can
not even determine what terminal goes down first - another one, much more time idle than
the one shwoing the "vmstat 5" output, is still alive! 

i consider this a serious bug and it is no benefit what happened since this "fancy"
update. :-(
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 473 bytes
Desc: OpenPGP digital signature
URL: <http://lists.freebsd.org/pipermail/freebsd-current/attachments/20160402/0c0b2ae5/attachment.sig>