Does Diego support memory swap?


Will Pragnell <wpragnell@...>
 

Hi Sam,

Sorry for the slow response - Monday and Friday were public holidays in the
UK (where the Garden team are based) so we didn't get a chance to look in
to this.

I think your understanding of that code is correct. I'm not sure why
`/proc/meminfo` is reporting those values for SwapTotal and SwapFree. I'll
try some experiments of my own and see if I can get to the bottom of it.

Best,
Will

On 28 March 2016 at 03:41, Sam Dai <sam.dai(a)servicemax.com> wrote:

According to this code
https://github.com/cloudfoundry-incubator/garden-linux/blob/master/linux_container/limits.go#L74-L75,
memory.limit_in_bytes and memory.memsw.limit_in_bytes are set to the same
limit value, it looks like when memory usage exceeds the limit, the kernel
of diego won't swap out any pages


Sam Dai
 

According to this code https://github.com/cloudfoundry-incubator/garden-linux/blob/master/linux_container/limits.go#L74-L75, memory.limit_in_bytes and memory.memsw.limit_in_bytes are set to the same limit value, it looks like when memory usage exceeds the limit, the kernel of diego won't swap out any pages


Sam Dai <dayfei2000@...>
 

According to this code https://github.com/cloudfoundry-incubator/garden-linux/blob/master/linux_container/limits.go#L74-L75 <https://github.com/cloudfoundry-incubator/garden-linux/blob/master/linux_container/limits.go#L74-L75>, memory.limit_in_bytes and memory.memsw.limit_in_bytes are set to the same limit value, it looks like when memory usage exceeds the limit, the kernel of diego won't swap out any pages


Sam Dai
 

Hi Will,
Thanks your reply, hope can get response from Garden-Linux soon.

Thanks,
Sam


Will Pragnell <wpragnell@...>
 

Hi Sam,

The thread you link from the archives discusses Warden exclusively, which
is the container engine used in the DEAs. Diego instead uses Garden-Linux
[1], which was originally a rewrite of Warden, but doesn't have identical
behaviour at this point.

I'm going to check in with some of the Garden-Linux engineers to figure out
a proper response to your query. Hopefully the above at least clears up
some of the confusion in the meantime.

Best,
Will

[1]: https://github.com/cloudfoundry-incubator/garden-linux

On 21 March 2016 at 12:50, Sam Dai <sam.dai(a)servicemax.com> wrote:

And after I ssh to app container using command "cf ssh app", then execute
command "cat /proc/meminfo", show the following information:
SwapTotal: 1048572 kB
SwapFree: 13180 kB
According to this information, memory swap works in diego, but where do I
configure the value of SwapTotal?


Sam Dai
 

And after I ssh to app container using command "cf ssh app", then execute command "cat /proc/meminfo", show the following information:
SwapTotal: 1048572 kB
SwapFree: 13180 kB
According to this information, memory swap works in diego, but where do I configure the value of SwapTotal?


Sam Dai
 

Hi all,
I just saw this page
https://lists.cloudfoundry.org/archives/list/cf-dev(a)lists.cloudfoundry.org/thread/QUPLENMHRESTGAIQFTG6MXRU7V6YZ4SA/#U6QUJFZEXDKLM5PMVPZRQQN4YUXIKAOF,
it looks like when memory usage exceeds the limit, the kernel of diego
won't swap out any pages to avoid the oom killer. But when I executed the
command "bosh vms --vitals", found the value of Swap Usage for cell_z1/0 is
"100% (1021.5M)", It looks like there is memory swap in diego cell, so
want to confirm if there is memory swap in deigo cell?

Thanks,
Sam