varnish 2.0.4 questions - no IMS, no persistence cache - please help

[GaneshKumar Natarajan]

Thanks  Tollef Fog Heen for the response.
> | 3. mmap storage : max i can configure is 340 GB.
> This looks weird.  Can you tell us something about what OS and kernel
> versions you are running?

Please find the details below. Let me know what i could try to
increase mmap storage from my current limitation of 340 G.
details:
OS:

Red Hat Enterprise Linux AS release 4 (Nahant Update 8)

uname -a
Linux 2.6.9-89.ELsmp #1 SMP Mon Apr 20 10:33:05 EDT 2009 x86_64 x86_64
x86_64 GNU/Linux
disk:
/dev/mapper/vg0-cache0
                           173         1       164   1% /squid/cache0
/dev/mapper/vg1-cache1
                           275         6       255   3% /squid/cache1
/dev/mapper/vg2-cache2
                           275         6       255   3% /squid/cache2
/dev/mapper/vg3-cache3
                           275         6       255   3% /squid/cache3
/dev/mapper/vg4-cache4
                           275         6       255   3% /squid/cache4
/dev/mapper/vg5-cache5
                           275         6       255   3% /squid/cache5

[icds at mdtnj120sics ~]$ cat /proc/meminfo
MemTotal:     32939168 kB
MemFree:        154296 kB
Buffers:        476836 kB
Cached:       16745252 kB
SwapCached:          0 kB
Active:       28386124 kB
Inactive:      1939176 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:     32939168 kB
LowFree:        154296 kB
SwapTotal:    67108856 kB
SwapFree:     67108616 kB
Dirty:               0 kB
Writeback:           0 kB
Mapped:       13124212 kB
Slab:          2374916 kB
CommitLimit:  83578440 kB
Committed_AS: 14006428 kB
PageTables:      28520 kB
VmallocTotal: 536870911 kB
VmallocUsed:    295936 kB
VmallocChunk: 536574591 kB
HugePages_Total:     0
HugePages_Free:      0
Hugepagesize:     2048 kB








> | 3. mmap storage : max i can configure is 340 GB.
> |
> | detail::
> | I was able to use only 340 GB of cache. any size after this, i would get error.
> | child (25790) Started
> | Pushing vcls failed: dlopen(./vcl.1P9zoqAU.so): ./vcl.1P9zoqAU.so:
> | failed to map segment from shared object: Cannot allocate memory
>
> This looks weird.  Can you tell us something about what OS and kernel
> versions you are running?


On Fri, Oct 23, 2009 at 2:00 AM, Tollef Fog Heen
<tfheen at redpill-linpro.com> wrote:
> ]] GaneshKumar Natarajan
>
> | 1. varnish doesn't send IMS request, when the object expires.
>
> Correct.  This is somewhat hard to do, but we see the request coming in
> regularly so it's something we might want to change at some point.  I
> don't believe there is any way to achieve this using VCL.
>
> | 2. Varnish cache is not persistent.
>
> Correct, this is being fixed for 2.1.  (It's the major feature for 2.1.)
>
> | 3. mmap storage : max i can configure is 340 GB.
> |
> | detail::
> | I was able to use only 340 GB of cache. any size after this, i would get error.
> | child (25790) Started
> | Pushing vcls failed: dlopen(./vcl.1P9zoqAU.so): ./vcl.1P9zoqAU.so:
> | failed to map segment from shared object: Cannot allocate memory
>
> This looks weird.  Can you tell us something about what OS and kernel
> versions you are running?
>
> | 4. I tried malloc storage option.
> | Question:
> | i have system of 32 GB physical ram and my swap storage is 65 GB.
> | harddisk storage - 1.5 TB ( distribued in 5 cache directoreys
> | /cach0,.../cache1 ).
> | What is the best optimal malloc storage i can use to achive greater performance?
> | -s malloc, [ size ] ???
>
> It depends on your setup and your traffic patterns, so it's usually best
> to try some different ones.
>
> | 5. what is the difference between using malloc or mmap?
> |
> | Help me to move onto varnish world and convince others in my team.
>
> malloc is, well, using malloc to allocate the memory, letting the system
> swap handle any page-outs.  mmap is just mmap-ing a large file, which
> still leaves it to the system to page out the unused bits, but often
> somewhat different code paths.  Which one is better depends on OS,
> traffic pattern, amount of memory, etc.
>
> --
> Tollef Fog Heen
> Redpill Linpro -- Changing the game!
> t: +47 21 54 41 73
>



-- 
Regards,
Gany