• 爱情文章
  • 亲情文章
  • 友情文章
  • 生活随笔
  • 校园文章
  • 经典文章
  • 人生哲理
  • 励志文章
  • 搞笑文章
  • 心情日记
  • 英语文章
  • 范文大全
  • 作文大全
  • 新闻阅读
  • 当前位置: 山茶花美文网 > 作文大全 > 正文

    linux,mysql,命令,大全_linux常用命令全集

    时间:2020-05-25来源:山茶花美文网 本文已影响 山茶花美文网手机站

    也许你还在为刚才动态内容获得7336.76 reqs/s的吞吐率感到振奋,等等,理想和现实是有差距的,你要忍受现实的残酷,别忘了,我们压力测试中的动态内容都处于全缓存情况下,也就是每次请求都命中缓存,这在现实中往往是不可能的。

    首先,缓存区空间大小是有限的,而我们的站点可能有大量的内容需要被缓存,而不像前边压力测试时只有一个内容。一旦缓存区被装满,那么缓存管理器便会淘汰一些它认为不再需要的缓存内容,比如通过LRU(最近最少使用算法)将使用频率较低的缓存内容淘汰出去,但是,这里判断“不常使用”的标准是不严格的,也许被淘汰的内容就是你将要访问的下一个内容,这便影响了它的命中率。

    其次,缓存的过期时间也影响到它的命中率,假如有效期很短,为10秒,那么最少10秒便会有一次无法命中。

    还有,有些内容可能根本没有被代理服务器缓存,比如这些内容包含了set-cookie等不可缓存的HTTP头信息,导致反向代理不会缓存它们,并且在浏览器请求它们的时候也不会去缓存区查找。这是影响命中率的一个重要因素,但往往被我们所忽略。

    幸运的是,这些问题我们都可以轻松的解决,前提是,我们需要了解反向代理缓存的实时工作状态,比如Varnish便提供了一个命令行的状态监控程序varnishstat,我们打开它,便看到了当前时刻的状态,如下:

    client_conn 9908723 94.05 Client connections accepted

    client_drop 0 0.00 Connection dropped, no sess/wrk

    client_req 16433490 155.99 Client requests received

    cache_hit 8751732 83.07 Cache hits

    cache_hitpass 42592 0.40 Cache hits for pass

    cache_miss 7573389 71.89 Cache misses

    backend_conn 3889845 36.92 Backend conn. success

    backend_unhealthy 220 0.00 Backend conn. not attempted

    backend_busy 0 0.00 Backend conn. too many

    backend_fail 4536 0.04 Backend conn. failures

    backend_reuse 3780212 35.88 Backend conn. reuses

    backend_toolate 3866687 36.70 Backend conn. was closed

    backend_recycle 7646677 72.58 Backend conn. recycles

    backend_unused 0 0.00 Backend conn. unused

    fetch_head 57 0.00 Fetch head

    fetch_length 155097 1.47 Fetch with Length

    fetch_chunked 7508522 71.27 Fetch chunked

    fetch_eof 0 0.00 Fetch EOF

    fetch_bad 0 0.00 Fetch had bad headers

    fetch_close 3982 0.04 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 1033 . N struct sess_mem

    n_sess 633 . N struct sess

    n_object 1016443 . N struct object

    n_vampireobject 0 . N unresurrected objects

    n_objectcore 1017564 . N struct objectcore

    n_objecthead 982903 . N struct objecthead

    n_smf 2647421 . N struct smf

    n_smf_frag 622470 . N small free smf

    n_smf_large 3 . N large free smf

    n_vbe_conn 12 . N struct vbe_conn

    n_wrk 8000 . N worker threads

    n_wrk_create 8000 0.08 N worker threads created

    n_wrk_failed 0 0.00 N worker threads not created

    n_wrk_max 11021 0.10 N worker threads limited

    n_wrk_queue 0 0.00 N queued work requests

    n_wrk_overflow 2441 0.02 N overflowed work requests

    n_wrk_drop 0 0.00 N dropped work requests

    n_backend 4 . N backends

    n_expired 6344546 . N expired objects

    n_lru_nuked 183957 . N LRU nuked objects

    n_lru_saved 0 . N LRU saved objects

    n_lru_moved 3692170 . N LRU moved objects

    n_deathrow 0 . N objects on deathrow

    losthdr 84 0.00 HTTP header overflows

    n_objsendfile 0 0.00 Objects sent with sendfile

    n_objwrite 15466812 146.81 Objects sent with write

    n_objoverflow 0 0.00 Objects overflowing workspace

    s_sess 9906155 94.03 Total Sessions

    s_req 16433490 155.99 Total Requests

    s_pipe 37 0.00 Total pipe

    s_pass 108252 1.03 Total pass

    s_fetch 7667658 72.78 Total fetch

    s_hdrbytes 7187255662 68221.35 Total header bytes

    s_bodybytes 111592032839 1059230.32 Total body bytes

    sess_closed 1905544 18.09 Session Closed

    sess_pipeline 0 0.00 Session Pipeline

    sess_readahead 0 0.00 Session Read Ahead

    sess_linger 15277717 145.02 Session Linger

    sess_herd 13547370 128.59 Session herd

    shm_records 1028855796 9765.89 SHM records

    shm_writes 77957008 739.97 SHM writes

    shm_flushes 131005 1.24 SHM flushes due to overflow

    shm_cont 144281 1.37 SHM MTX contention

    shm_cycles 427 0.00 SHM cycles through buffer

    sm_nreq 15306717 145.29 allocator requests

    sm_nobj 2024948 . outstanding allocations

    sm_balloc 13595295744 . bytes allocated

    sm_bfree 40091795456 . bytes free

    sma_nreq 0 0.00 SMA allocator requests

    sma_nobj 0 . SMA outstanding allocations

    sma_nbytes 0 . SMA outstanding bytes

    sma_balloc 0 . SMA bytes allocated

    sma_bfree 0 . SMA bytes free

    sms_nreq 14062 0.13 SMS allocator requests

    sms_nobj 0 . SMS outstanding allocations

    sms_nbytes 487 . SMS outstanding bytes

    sms_balloc 6844837 . SMS bytes allocated

    sms_bfree 6846298 . SMS bytes freed

    backend_req 7668789 72.79 Backend requests made

    n_vcl 1 0.00 N vcl total

    n_vcl_avail 1 0.00 N vcl available

    n_vcl_discard 0 0.00 N vcl discarded

    • linux,mysql,命令,大全_linux常用命令全集 相关文章:
    • 爱情文章
    • 亲情文章
    • 友情文章
    • 随笔
    • 哲理
    • 励志
    • 范文大全