Config
--------------------------------------------------
-T localhost:6082
-f /etc/varnish/default.vcl
-S /etc/varnish/secret
-u web
-s malloc,32M
-p thread_pools=2
-p thread_pool_min=2
-p thread_pool_add_delay=2
-p thread_pool_max=16
-p cli_timeout=20
-p session_linger=20

Session linger 20
--------------------------------------------------
varnishstat -1

client_conn                51         0.32 Client connections accepted
client_drop                 0         0.00 Connection dropped, no sess/wrk
client_req              15982       101.15 Client requests received
cache_hit               14863        94.07 Cache hits
cache_hitpass             216         1.37 Cache hits for pass
cache_miss                903         5.72 Cache misses
backend_conn             1112         7.04 Backend conn. success
backend_unhealthy            0         0.00 Backend conn. not attempted
backend_busy                0         0.00 Backend conn. too many
backend_fail                0         0.00 Backend conn. failures
backend_reuse               0         0.00 Backend conn. reuses
backend_toolate             0         0.00 Backend conn. was closed
backend_recycle             0         0.00 Backend conn. recycles
backend_unused              0         0.00 Backend conn. unused
fetch_head                  0         0.00 Fetch head
fetch_length             1106         7.00 Fetch with Length
fetch_chunked               6         0.04 Fetch chunked
fetch_eof                   0         0.00 Fetch EOF
fetch_bad                   0         0.00 Fetch had bad headers
fetch_close                 0         0.00 Fetch wanted close
fetch_oldhttp               0         0.00 Fetch pre HTTP/1.1 closed
fetch_zero                  0         0.00 Fetch zero len
fetch_failed                0         0.00 Fetch failed
n_sess_mem                 29          .   N struct sess_mem
n_sess                     13          .   N struct sess
n_object                  896          .   N struct object
n_vampireobject             0          .   N unresurrected objects
n_objectcore              910          .   N struct objectcore
n_objecthead              917          .   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                  0          .   N struct vbe_conn
n_wrk                      16          .   N worker threads
n_wrk_create               16         0.10 N worker threads created
n_wrk_failed                0         0.00 N worker threads not created
n_wrk_max                   0         0.00 N worker threads limited
n_wrk_queue                 0         0.00 N queued work requests
n_wrk_overflow            461         2.92 N overflowed work requests
n_wrk_drop                  0         0.00 N dropped work requests
n_backend                   2          .   N backends
n_expired                   0          .   N expired objects
n_lru_nuked                 0          .   N LRU nuked objects
n_lru_saved                 0          .   N LRU saved objects
n_lru_moved               252          .   N LRU moved objects
n_deathrow                  0          .   N objects on deathrow
losthdr                     0         0.00 HTTP header overflows
n_objsendfile               0         0.00 Objects sent with sendfile
n_objwrite              15960       101.01 Objects sent with write
n_objoverflow               0         0.00 Objects overflowing workspace
s_sess                     51         0.32 Total Sessions
s_req                   15983       101.16 Total Requests
s_pipe                      0         0.00 Total pipe
s_pass                    216         1.37 Total pass
s_fetch                  1112         7.04 Total fetch
s_hdrbytes            2958691     18725.89 Total header bytes
s_bodybytes          15878078    100494.16 Total body bytes
sess_closed                10         0.06 Session Closed
sess_pipeline               0         0.00 Session Pipeline
sess_readahead              0         0.00 Session Read Ahead
sess_linger             15976       101.11 Session Linger
sess_herd               15051        95.26 Session herd
shm_records            628577      3978.34 SHM records
shm_writes              32480       205.57 SHM writes
shm_flushes                 0         0.00 SHM flushes due to overflow
shm_cont                  646         4.09 SHM MTX contention
shm_cycles                  0         0.00 SHM cycles through buffer
sm_nreq                     0         0.00 allocator requests
sm_nobj                     0          .   outstanding allocations
sm_balloc                   0          .   bytes allocated
sm_bfree                    0          .   bytes free
sma_nreq                 2008        12.71 SMA allocator requests
sma_nobj                 1792          .   SMA outstanding allocations
sma_nbytes             979178          .   SMA outstanding bytes
sma_balloc            4805896          .   SMA bytes allocated
sma_bfree             3826718          .   SMA bytes free
sms_nreq                    7         0.04 SMS allocator requests
sms_nobj                    0          .   SMS outstanding allocations
sms_nbytes                  0          .   SMS outstanding bytes
sms_balloc               3416          .   SMS bytes allocated
sms_bfree                3416          .   SMS bytes freed
backend_req              1112         7.04 Backend requests made
n_vcl                       1         0.01 N vcl total
n_vcl_avail                 1         0.01 N vcl available
n_vcl_discard               0         0.00 N vcl discarded
n_purge                     1          .   N total active purges
n_purge_add                 1         0.01 N new purges added
n_purge_retire              0         0.00 N old purges deleted
n_purge_obj_test            0         0.00 N objects tested
n_purge_re_test             0         0.00 N regexps tested against
n_purge_dups                0         0.00 N duplicate purges removed
hcb_nolock              15992       101.22 HCB Lookups without lock
hcb_lock                  903         5.72 HCB Lookups with lock
hcb_insert                903         5.72 HCB Inserts
esi_parse                   0         0.00 Objects ESI parsed (unlock)
esi_errors                  0         0.00 ESI parse errors (unlock)
accept_fail                 0         0.00 Accept failures
client_drop_late            0         0.00 Connection dropped late
uptime                    158         1.00 Client uptime



No session linger
--------------------------------------------------

client_conn                44         1.10 Client connections accepted
client_drop                 0         0.00 Connection dropped, no sess/wrk
client_req              13081       327.02 Client requests received
cache_hit               12029       300.73 Cache hits
cache_hitpass             196         4.90 Cache hits for pass
cache_miss                854        21.35 Cache misses
backend_conn             1058        26.45 Backend conn. success
backend_unhealthy            0         0.00 Backend conn. not attempted
backend_busy                0         0.00 Backend conn. too many
backend_fail              119         2.98 Backend conn. failures
backend_reuse               0         0.00 Backend conn. reuses
backend_toolate             0         0.00 Backend conn. was closed
backend_recycle             0         0.00 Backend conn. recycles
backend_unused              0         0.00 Backend conn. unused
fetch_head                  0         0.00 Fetch head
fetch_length             1047        26.18 Fetch with Length
fetch_chunked               5         0.12 Fetch chunked
fetch_eof                   0         0.00 Fetch EOF
fetch_bad                   0         0.00 Fetch had bad headers
fetch_close                 0         0.00 Fetch wanted close
fetch_oldhttp               0         0.00 Fetch pre HTTP/1.1 closed
fetch_zero                  0         0.00 Fetch zero len
fetch_failed                0         0.00 Fetch failed
n_sess_mem                 29          .   N struct sess_mem
n_sess                     13          .   N struct sess
n_object                  854          .   N struct object
n_vampireobject             0          .   N unresurrected objects
n_objectcore              869          .   N struct objectcore
n_objecthead              869          .   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                  0          .   N struct vbe_conn
n_wrk                      16          .   N worker threads
n_wrk_create               16         0.40 N worker threads created
n_wrk_failed                0         0.00 N worker threads not created
n_wrk_max                   0         0.00 N worker threads limited
n_wrk_queue                 0         0.00 N queued work requests
n_wrk_overflow             63         1.57 N overflowed work requests
n_wrk_drop                  0         0.00 N dropped work requests
n_backend                   2          .   N backends
n_expired                   0          .   N expired objects
n_lru_nuked                 0          .   N LRU nuked objects
n_lru_saved                 0          .   N LRU saved objects
n_lru_moved               228          .   N LRU moved objects
n_deathrow                  0          .   N objects on deathrow
losthdr                     0         0.00 HTTP header overflows
n_objsendfile               0         0.00 Objects sent with sendfile
n_objwrite              13110       327.75 Objects sent with write
n_objoverflow               0         0.00 Objects overflowing workspace
s_sess                     44         1.10 Total Sessions
s_req                   13081       327.02 Total Requests
s_pipe                      0         0.00 Total pipe
s_pass                    198         4.95 Total pass
s_fetch                  1052        26.30 Total fetch
s_hdrbytes            2426109     60652.72 Total header bytes
s_bodybytes          13327473    333186.83 Total body bytes
sess_closed                 9         0.23 Session Closed
sess_pipeline               0         0.00 Session Pipeline
sess_readahead              0         0.00 Session Read Ahead
sess_linger             13069       326.73 Session Linger
sess_herd                 357         8.93 Session herd
shm_records            510138     12753.45 SHM records
shm_writes              14730       368.25 SHM writes
shm_flushes                 0         0.00 SHM flushes due to overflow
shm_cont                    8         0.20 SHM MTX contention
shm_cycles                  0         0.00 SHM cycles through buffer
sm_nreq                     0         0.00 allocator requests
sm_nobj                     0          .   outstanding allocations
sm_balloc                   0          .   bytes allocated
sm_bfree                    0          .   bytes free
sma_nreq                 1918        47.95 SMA allocator requests
sma_nobj                 1720          .   SMA outstanding allocations
sma_nbytes             891969          .   SMA outstanding bytes
sma_balloc            4356287          .   SMA bytes allocated
sma_bfree             3464318          .   SMA bytes free
sms_nreq                    0         0.00 SMS allocator requests
sms_nobj                    0          .   SMS outstanding allocations
sms_nbytes                  0          .   SMS outstanding bytes
sms_balloc                  0          .   SMS bytes allocated
sms_bfree                   0          .   SMS bytes freed
backend_req              1058        26.45 Backend requests made
n_vcl                       1         0.03 N vcl total
n_vcl_avail                 1         0.03 N vcl available
n_vcl_discard               0         0.00 N vcl discarded
n_purge                     1          .   N total active purges
n_purge_add                 1         0.03 N new purges added
n_purge_retire              0         0.00 N old purges deleted
n_purge_obj_test            0         0.00 N objects tested
n_purge_re_test             0         0.00 N regexps tested against
n_purge_dups                0         0.00 N duplicate purges removed
hcb_nolock              13125       328.12 HCB Lookups without lock
hcb_lock                  860        21.50 HCB Lookups with lock
hcb_insert                860        21.50 HCB Inserts
esi_parse                   0         0.00 Objects ESI parsed (unlock)
esi_errors                  0         0.00 ESI parse errors (unlock)
accept_fail                 0         0.00 Accept failures
client_drop_late            0         0.00 Connection dropped late
uptime                     40         1.00 Client uptime


session_linger=150
--------------------------------------------------

client_conn                16         0.47 Client connections accepted
client_drop                 0         0.00 Connection dropped, no sess/wrk
client_req               5465       160.74 Client requests received
cache_hit                5233       153.91 Cache hits
cache_hitpass             224         6.59 Cache hits for pass
cache_miss                  8         0.24 Cache misses
backend_conn              235         6.91 Backend conn. success
backend_unhealthy            0         0.00 Backend conn. not attempted
backend_busy                0         0.00 Backend conn. too many
backend_fail               40         1.18 Backend conn. failures
backend_reuse               0         0.00 Backend conn. reuses
backend_toolate             0         0.00 Backend conn. was closed
backend_recycle             0         0.00 Backend conn. recycles
backend_unused              0         0.00 Backend conn. unused
fetch_head                  0         0.00 Fetch head
fetch_length              230         6.76 Fetch with Length
fetch_chunked               2         0.06 Fetch chunked
fetch_eof                   0         0.00 Fetch EOF
fetch_bad                   0         0.00 Fetch had bad headers
fetch_close                 0         0.00 Fetch wanted close
fetch_oldhttp               0         0.00 Fetch pre HTTP/1.1 closed
fetch_zero                  0         0.00 Fetch zero len
fetch_failed                0         0.00 Fetch failed
n_sess_mem                 18          .   N struct sess_mem
n_sess                     15          .   N struct sess
n_object                    8          .   N struct object
n_vampireobject             0          .   N unresurrected objects
n_objectcore               15          .   N struct objectcore
n_objecthead               15          .   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                  0          .   N struct vbe_conn
n_wrk                       7          .   N worker threads
n_wrk_create                7         0.21 N worker threads created
n_wrk_failed                0         0.00 N worker threads not created
n_wrk_max                   0         0.00 N worker threads limited
n_wrk_queue                 8         0.24 N queued work requests
n_wrk_overflow             12         0.35 N overflowed work requests
n_wrk_drop                  0         0.00 N dropped work requests
n_backend                   2          .   N backends
n_expired                   0          .   N expired objects
n_lru_nuked                 0          .   N LRU nuked objects
n_lru_saved                 0          .   N LRU saved objects
n_lru_moved                71          .   N LRU moved objects
n_deathrow                  0          .   N objects on deathrow
losthdr                     0         0.00 HTTP header overflows
n_objsendfile               0         0.00 Objects sent with sendfile
n_objwrite               5493       161.56 Objects sent with write
n_objoverflow               0         0.00 Objects overflowing workspace
s_sess                      8         0.24 Total Sessions
s_req                    5465       160.74 Total Requests
s_pipe                      0         0.00 Total pipe
s_pass                    224         6.59 Total pass
s_fetch                   232         6.82 Total fetch
s_hdrbytes            1045352     30745.65 Total header bytes
s_bodybytes           6625740    194874.71 Total body bytes
sess_closed                 1         0.03 Session Closed
sess_pipeline               0         0.00 Session Pipeline
sess_readahead              0         0.00 Session Read Ahead
sess_linger              5458       160.53 Session Linger
sess_herd                   0         0.00 Session herd
shm_records            206887      6084.91 SHM records
shm_writes               5797       170.50 SHM writes
shm_flushes                 0         0.00 SHM flushes due to overflow
shm_cont                    0         0.00 SHM MTX contention
shm_cycles                  0         0.00 SHM cycles through buffer
sm_nreq                     0         0.00 allocator requests
sm_nobj                     0          .   outstanding allocations
sm_balloc                   0          .   bytes allocated
sm_bfree                    0          .   bytes free
sma_nreq                  243         7.15 SMA allocator requests
sma_nobj                   16          .   SMA outstanding allocations
sma_nbytes              26644          .   SMA outstanding bytes
sma_balloc            3547627          .   SMA bytes allocated
sma_bfree             3520983          .   SMA bytes free
sms_nreq                    0         0.00 SMS allocator requests
sms_nobj                    0          .   SMS outstanding allocations
sms_nbytes                  0          .   SMS outstanding bytes
sms_balloc                  0          .   SMS bytes allocated
sms_bfree                   0          .   SMS bytes freed
backend_req               235         6.91 Backend requests made
n_vcl                       1         0.03 N vcl total
n_vcl_avail                 1         0.03 N vcl available
n_vcl_discard               0         0.00 N vcl discarded
n_purge                     1          .   N total active purges
n_purge_add                 1         0.03 N new purges added
n_purge_retire              0         0.00 N old purges deleted
n_purge_obj_test            0         0.00 N objects tested
n_purge_re_test             0         0.00 N regexps tested against
n_purge_dups                0         0.00 N duplicate purges removed
hcb_nolock               5493       161.56 HCB Lookups without lock
hcb_lock                    8         0.24 HCB Lookups with lock
hcb_insert                  8         0.24 HCB Inserts
esi_parse                   0         0.00 Objects ESI parsed (unlock)
esi_errors                  0         0.00 ESI parse errors (unlock)
accept_fail                 0         0.00 Accept failures
client_drop_late            0         0.00 Connection dropped late
uptime                     34         1.00 Client uptime