Memory Usage when using malloc

[Audun Ytterdal]

I need some help to understand this

I have a 64bit server with 32GB of RAM and 60GB SWAP

And varnish is running with these parameters

/usr/sbin/varnishd -a :80 -f /etc/varnish/nettby.vcl -T 127.0.0.1:82 -t
120 -u varnish -g varnish -p thread_pool_add_delay 100 -p
thread_pool_timeout 600 -p client_http11 on -p lru_interval 3600 -s
malloc,30G -P /var/run/varnish.pid

malloc'ed 30G of memory.. So in theory I should not even need swap.

But

[root at sol ~]# free -m
             total       used       free     shared    buffers     cached
Mem:         32242      31735        507          0          0         92
-/+ buffers/cache:      31642        600
Swap:        59871      51322       8549


The machine is using 51GB of swap and is swapping in pages frequently

[root at sol ~]# vmstat 1
procs -----------memory---------- ---swap-- -----io---- --system--
-----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy
id wa st
 0  0 52549748 446992    780  96284   29   11    48   157    1    1  4 
2 92  1  0
 0  0 52549708 530360    780  96348  280    0   280     0 9654 6935  4 
8 87  1  0
 0  0 52549708 528160    780  96420    0    0     0     0 6785 7560  2 
2 96  0  0
 0  0 52549664 526668    780  96316  316    0   316     0 6570 7350  2 
2 95  1  0
 0  0 52549648 524932    780  96396  104    0   104     0 6300 7456  2 
1 96  0  0
 0  0 52549644 523372    780  96400   28    0    28     0 6013 7099  2 
2 96  0  0
 0  0 52549640 521884    788  96424   28    0    28    28 5649 7343  2 
2 96  0  0



[root at sol ~]# varnishstat -1
client_conn        2089633996       362.23 Client connections accepted
client_req         8345199749      1446.62 Client requests received
cache_hit          8289156139      1436.90 Cache hits
cache_hitpass            1610         0.00 Cache hits for pass
cache_miss           53623537         9.30 Cache misses
backend_conn         53621117         9.30 Backend connections success
backend_fail             4031         0.00 Backend connections failures
backend_reuse               0         0.00 Backend connections reuses
backend_recycle             0         0.00 Backend connections recycles
backend_unused              0         0.00 Backend connections unused
n_srcaddr                7689          .   N struct srcaddr
n_srcaddr_act            4164          .   N active struct srcaddr
n_sess_mem              59601          .   N struct sess_mem
n_sess                  64719          .   N struct sess
n_object              2025596          .   N struct object
n_objecthead          2025576          .   N struct objecthead
n_smf                       0          .   N struct smf
n_smf_frag                  0          .   N small free smf
n_smf_large                 0          .   N large free smf
n_vbe_conn                106          .   N struct vbe_conn
n_bereq                    96          .   N struct bereq
n_wrk                      78          .   N worker threads
n_wrk_create            15968         0.00 N worker threads created
n_wrk_failed                0         0.00 N worker threads not created
n_wrk_max           191919689        33.27 N worker threads limited
n_wrk_queue                 0         0.00 N queued work requests
n_wrk_overflow      210128619        36.43 N overflowed work requests
n_wrk_drop           31202342         5.41 N dropped work requests
n_backend                   1          .   N backends
n_expired            31600718          .   N expired objects
n_lru_nuked          20008124          .   N LRU nuked objects
n_lru_saved                 0          .   N LRU saved objects
n_lru_moved         779599235          .   N LRU moved objects
n_deathrow                  0          .   N objects on deathrow
losthdr                   196         0.00 HTTP header overflows
n_objsendfile               0         0.00 Objects sent with sendfile
n_objwrite         6674989721      1157.09 Objects sent with write
n_objoverflow               0         0.00 Objects overflowing workspace
s_sess             2073648637       359.46 Total Sessions
s_req              8345234372      1446.62 Total Requests
s_pipe                      0         0.00 Total pipe
s_pass                      0         0.00 Total pass
s_fetch              53620083         9.29 Total fetch
s_hdrbytes       2924438007698    506943.34 Total header bytes
s_bodybytes      13839780950697   2399088.22 Total body bytes
sess_closed          54123498         9.38 Session Closed
sess_pipeline               0         0.00 Session Pipeline
sess_readahead       42322579         7.34 Session Read Ahead
sess_herd          8270331676      1433.64 Session herd
shm_records      347828089203     60295.05 SHM records
shm_writes        14631506809      2536.33 SHM writes
shm_flushes            908314         0.16 SHM flushes due to overflow
shm_cont             14245861         2.47 SHM MTX contention
sm_nreq                     0         0.00 allocator requests
sm_nobj                     0          .   outstanding allocations
sm_balloc                   0          .   bytes allocated
sm_bfree                    0          .   bytes free
sma_nreq            127269201        22.06 SMA allocator requests
sma_nobj              4019319          .   SMA outstanding allocations
sma_nbytes        32212251961          .   SMA outstanding bytes
sma_balloc       891934739829          .   SMA bytes allocated
sma_bfree        859722487868          .   SMA bytes free
backend_req          53621117         9.30 Backend requests made




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