Posted 2021-05-02 SpringBoot

鐩稿叧鍘嗗彶鏂囩珷锛?/strong>闃呰鏈枃涔嬪墠锛屾偍鍙兘闇€瑕佸厛鐪嬩笅涔嬪墠鐨勭郴鍒?/strong>馃憞锛?/strong>

銆?/span>鍐呭瓨绠＄悊闅句笉闅撅紝涓浗灞变笢鎵捐摑缈?/span>銆?/span>

鎮熺氦锛?/span>甯堝倕锛屽笀鍌咃紝鍜变滑杩欏懆瀛︿範浠€涔堬紵

甯堝倕锛氬瀛愬彲鏁欎篃锛屽鏃犳澧冿紝姣忓懆涓€瀛︺€傝繖鑺傦紝鍜变滑涓昏鏄璁茶鍐呭瓨绠＄悊锛屾湁鐐瑰皬闅惧憪锛屾嬁涓皬鏉垮嚦锛屽甫涓婅€虫湹濂藉ソ鍚惂銆?/span>

鎮熺氦锛氬ソ鍚э紝甯堝倕锛岃繖灏辨妸韬綋娲椾竴涓嬶紝椹笂灏辨潵銆?/span>

甯堝倕锛氣€︹€?/span>

涓€銆佸唴瀛樼鐞嗘満鍒?/span>

memcached榛樿鎯呭喌涓嬮噰鐢ㄤ簡鍚嶄负Slab Allocator锛堝唴瀛樺垎閰嶇瓥鐣ワ級鐨勬満鍒跺垎閰嶃€佺鐞嗗唴瀛樸€傚湪璇ユ満鍒跺嚭鐜颁互鍓嶏紝鍐呭瓨鐨勫垎閰嶆槸閫氳繃瀵规墍鏈夎褰曠畝鍗曞湴杩涜malloc / free鏉ヨ繘琛岀殑銆備絾鏄紝杩欑鏂瑰紡浼氬鑷村唴瀛樼鐗囷紝鍔犻噸鎿嶄綔绯荤粺鍐呭瓨绠＄悊鍣ㄧ殑璐熸媴锛屾渶鍧忕殑鎯呭喌涓嬶紝浼氬鑷存搷浣滅郴缁熸瘮 memcached 杩涚▼鏈韩杩樻參銆係lab Allocator 灏辨槸涓鸿В鍐宠闂鑰岃癁鐢熺殑銆?/span>

1.1 Slab Allocator鍘熺悊

涓嬮潰鏉ョ湅鐪?Slab Allocator 鐨勫師鐞嗐€備笅闈㈡槸 memcached 鏂囨。涓殑 slab allocator 鐨勭洰鏍囷細

Theprimary goal of the slabs subsystem in memcached was to eliminate memoryfragmentation issues totally by using fixed颅size memory chunks coming from afew predetermined size classes.

涔熷氨鏄锛孲lab Allocator 鐨勫熀鏈師鐞嗘槸鎸夌収棰勫厛瑙勫畾鐨勫ぇ灏?/span>锛?/span>灏嗗垎閰嶇殑鍐呭瓨鍒嗗壊鎴愮壒瀹氶暱搴︾殑鍧?/span>锛屼互瀹屽叏瑙ｅ喅鍐呭瓨纰庣墖闂銆?/span>

       Slab Allocation 鐨勫師鐞嗙浉褰撶畝鍗曘€傚皢鍒嗛厤鐨勫唴瀛樺垎鍓叉垚鍚勭灏哄鐨勫潡锛坈hunk锛?/span>锛屽苟鎶?/span>灏哄鐩稿悓鐨勫潡鍒嗘垚缁?/span>锛坈hunk 鐨勯泦鍚堬級

鍙﹀slab allocator 杩樻湁閲嶅浣跨敤宸插垎閰嶇殑鍐呭瓨鐨勭洰鐨勩€備篃灏辨槸璇达紝鍒嗛厤鍒扮殑鍐呭瓨涓嶄細閲婃斁锛岃€屾槸閲嶅鍒╃敤銆?/span>

       濂藉惂锛屼粠涓婇潰鐨勬弿杩颁腑锛屾垜浠湁蹇呰鍏堜簡瑙ｄ竴浜涙蹇碉細

锛?锛?/span>Page锛氬垎閰嶇粰 Slab 鐨勫唴瀛樼┖闂达紝榛樿鏄?1MB銆傚垎閰嶇粰 Slab 涔嬪悗鏍规嵁 slab 鐨勫ぇ灏忓垏鍒嗘垚 chunk銆?/span>

锛?锛?/span>Chunk锛氬畠鏄皢鍐呭瓨鍒嗛厤缁欑敤鎴蜂娇鐢ㄧ殑鏈€灏忓崟鍏冿紝鐢ㄤ簬缂撳瓨璁板綍鐨勫唴瀛樼┖闂淬€?/span>

锛?锛?/span>SlabClass锛氱壒瀹氬ぇ灏忕殑 chunk 鐨勭粍銆?/span>

锛?锛?/span>item锛氱敤鎴疯瀛樺偍鐨勬暟鎹紝鍖呭惈key鍜寁alue锛屾渶缁堥兘瀛樺偍鍦╟hunk閲屻€?/span>

鐜板湪鍙互绠€鍗曠悊瑙ｄ笅 Slab allocation锛屽湪 Memcached 涓紝鍐呭瓨棣栧厛琚垎閰嶇粰涓€涓釜pages锛屾瘡涓?page 榛樿澶у皬閮芥槸 1MB锛屽亣璁?m鍚姩鍙傛暟鏄?64 M锛堝悗闈㈤兘浠?64M 璇存槑锛夛紝閭ｄ箞绯荤粺灏卞瓨鍦?64 涓?page銆?/span>

       姣忎釜 page 琚寚瀹氫负 slab-class锛宻lab-class 鐩稿綋浜庢瘡涓?page 鐨勫睘鎬э紝鏈鎸囧畾 slab-class 鐨?page 灏辨槸鏈垎閰嶇殑鍐呭瓨銆?/span>

       slab-class 鍐冲畾浜嗘瘡涓?page 瀛樺偍 item 鐨勫ぇ灏?/span>锛岀О涔嬩负 chunk锛宑hunnk 灏辨槸鐢ㄦ潵瀛樺偍 item 鐨勶紝鍦ㄥ悓涓€涓?page 涓紝鎵€鏈夌殑 chunk 澶у皬鏄竴鑷寸殑銆?/span>

       涓嶅悓鐨?slab-class 鍏?chunk 澶у皬鏄笉涓€鑷寸殑锛屽熀鏈笂鏄€掑鍏崇郴锛岄粯璁ゆ槸 1.25 姣斾緥鐨勫闀挎柟寮忋€?/span>

涓轰簡鐞嗚В page锛宻lab-class锛宑hunk鐨勫叧绯伙紝鍙互杩愯鍛戒护锛歮emcached -vv,寰楀埌濡備笅鏁版嵁锛?/span>

$ memcached -vv

 

slab class   1: chunksize        96 perslab   10922

slab class   2: chunksize       120 perslab    8738

slab class   3: chunksize       152 perslab    6898

slab class   4: chunksize       192 perslab    5461

slab class   5: chunksize       240 perslab    4369

slab class   6: chunksize       304 perslab    3449

slab class   7: chunksize       384 perslab    2730

slab class   8: chunksize       480 perslab    2184

slab class   9: chunksize       600 perslab    1747

...

slab class   39: chunksize  524288 perslab        2

BTW锛?/span>

锛?锛塻lab class 1 鍏?chunk 澶у皬鏄?96 瀛楄妭锛岄偅涔堝搴旂殑 page 鏈€澶氬彲浠ュ瓨鍌?10922 涓?chunk銆俿labclass 2 鏍规嵁 slab class 1 * 1.25锛?6*1.25=120锛夌殑鍏紡锛宑hunk 澶у皬鏄?120 涓瓧鑺傦紝瀵瑰簲鐨?page 鏈€澶氬彲浠ュ瓨鍌?8738 涓猚hunk锛屼緷娆＄被鎺ㄣ€?/span>

锛?锛夋垜浠湅鍒帮紝涓€鍏辨湁39涓猻lab锛岀涓€涓猻lab涓璫hunk澶у皬涓?6bytes锛岀浜屼釜涓?20bytes锛岀涓変釜涓?52bytes锛屾瘡涓猻lab涓璫hunk鐨勫ぇ灏忛兘涓嶄竴鏍凤紝杩欎釜chunk灏辨槸memcached鍏蜂綋瀛樺偍鏁版嵁鐨勫湴鏂广€?/span>

 

TBTW锛?/span>

锛?锛夊闀垮洜瀛愶細灏辨槸姣忎釜chunk涔嬮棿閫掑鐨勭郴鏁帮紝memcached鍐呭瓨鏄鍏堝垎绫荤殑锛屾瘡涓猚hunk鐨勫ぇ灏忓氨鏄€氳繃澧為暱鍥犲瓙鏉ヨ绠楃殑锛岄粯璁ょ殑澧為暱鍥犲瓙鎴栬€呰鏄闀跨郴鏁版槸1.25銆?/span>

锛?锛夐€氳繃澧為暱鍥犲瓙璁＄畻绗簩涓猚hunk澶у皬锛岀涓€涓猚hunk缁勶紙涔熷氨鏄痵lab class锛夌殑澶у皬鏄?6瀛楄妭锛?B(瀛楄妭)=8b(浣?锛夛紝澧為暱鍥犲瓙鏄?.25锛岄偅涔堢浜岀粍鐨刢hunk鐨勫ぇ灏忓氨搴旇鏄?6*1.25 = 120锛岀涓夌粍鐨刢hunk澶у皬灏辨槸120*1.25 = 152銆?/span>

锛?锛夎绠椾竴涓猵age鍙互瀛樺偍鐨勪釜鏁般€傛垜浠湅绗竴涓猻lab class1 : chunk鐨勫ぇ灏忔槸96瀛楄妭锛屽叡鍙互瀛樺偍10922涓紝鎬庝箞寰楀埌鐨勫憪锛屾垜浠煡閬撲竴涓猵age鏄?M锛宲age涓槸鐢辩浉鍚屽ぇ灏忕殑chunk鏋勬垚锛岄偅涔堝厑璁稿瓨鍌ㄧ殑涓暟=1M/96B=1024*1024B/96B=10922.67鈮?0922銆?/span>

 

1.2 鍦?Slab 涓紦瀛樿褰曠殑鍘熺悊

涓嬮潰璇存槑 memcached 濡備綍閽堝瀹㈡埛绔彂閫佺殑鏁版嵁閫夋嫨 slab 骞剁紦瀛樺埌 chunk 涓€?/span>

memcached鏍规嵁鏀跺埌鐨勬暟鎹殑澶у皬锛岄€夋嫨鏈€閫傚悎鏁版嵁澶у皬鐨?slab锛堝涓婂浘锛夈€俶emcached 涓繚瀛樼潃slab 鍐呯┖闂?chunk 鐨勫垪琛紝鏍规嵁璇ュ垪琛ㄩ€夋嫨 chunk锛岀劧鍚庡皢鏁版嵁缂撳瓨浜庡叾涓€?/span>

       閫氳繃涓婇潰鐨勫瓨鍌ㄦ柟寮忥紝鎴戜滑鑳界湅鍑篠labAllocator涔熷瓨鍦ㄤ竴浜涘紛绔€?/span>

1.3 Slab Allocator 鐨勭己鐐?/span>

SlabAllocator 瑙ｅ喅浜嗗唴瀛樼鐗囬棶棰橈紝浣嗘柊鐨勬満鍒朵篃缁?memcached 甯︽潵浜嗘柊鐨勯棶棰樸€傝繖涓棶棰樺氨鏄紝鐢变簬鍒嗛厤鐨勬槸鐗瑰畾闀垮害鐨勫唴瀛橈紝鍥犳鏃犳硶鏈夋晥鍒╃敤鍒嗛厤鐨勫唴瀛樸€備緥濡傦紝灏?100 瀛楄妭鐨勬暟鎹紦瀛樺埌 128 瀛楄妭鐨?chunk 涓紝鍓╀綑鐨?28 瀛楄妭灏辨氮璐逛簡銆?/span>

BTW锛氳繖閲岄渶瑕佹敞鎰忕殑鏄?/span>chunk涓笉浠呬粎瀛樻斁缂撳瓨瀵硅薄鐨剉alue锛岃€屼笖淇濆瓨浜嗙紦瀛樺璞＄殑key锛宔xpire time锛?flag绛夎缁嗕俊鎭€傛墍浠ュ綋set  1瀛楄妭鐨刬tem锛岄渶瑕佽繙杩?/span>澶т簬1瀛楄妭鐨勭┖闂村瓨鏀俱€?/span>

瀵逛簬璇ラ棶棰樼洰鍓嶈繕娌℃湁瀹岀編鐨勮В鍐虫柟妗堬紝浣嗗湪鏂囨。涓杞戒簡姣旇緝鏈夋晥鐨勮В鍐虫柟妗堛€傚鏋滈鍏堢煡閬撳鎴风鍙戦€佺殑鏁版嵁鐨勫叕鐢ㄥぇ灏忥紝鎴栬€呬粎缂撳瓨澶у皬鐩稿悓鐨勬暟鎹殑鎯呭喌涓嬶紝鍙浣跨敤閫傚悎鏁版嵁澶у皬鐨勭粍鐨勫垪琛紝灏卞彲浠ュ噺灏戞氮璐广€?/span>

 

浜屻€佹偀绾?00闂?/span>

2.1 濡備綍鏌ョ湅Memcached鍒嗛厤鐨勫唴瀛?/span>

       Memcached鐨勯粯璁ゅ垎閰嶇殑鍐呭瓨鏄?4M锛屾€庝箞鏌ョ湅鍛愶細

Mac鐩存帴浣跨敤鍛戒护锛?/span>

echo stats | nc 127.0.0.1 11211

Win涓嬮渶瑕佷娇鐢╰elnet杩炴帴锛岀劧鍚庤緭鍏tats锛?/span>

telnet 127.0.0.1 11211

#杩炴帴涔嬪悗锛岃緭鍏ヤ互涓嬫寚浠わ細

stats

BTW锛氫笂闈袱绉嶆柟寮廙AC閮芥敮鎸?/span>

       杩欐椂鍊欏彲浠ョ湅鍒癕emcached涓€婧滅殑淇℃伅锛?/span>

STAT pid77651

STAT uptime6208

STAT time1569563071

STAT version1.5.14

STATbytes_read 57

STATbytes_written 7579

STAT limit_maxbytes 67108864

STATaccepting_conns 1

鈥?/span>

STATdirect_reclaims 0

STATlru_bumps_dropped 0

       杩欓噷鎴彇浜嗕竴閮ㄥ垎淇℃伅锛屾湁鍏冲唴瀛樺ぇ灏忕殑鍊兼槸limit_maxbytes锛屾渶澶у瓧鑺備篃灏辨槸67108864 = 64*1024*1024 = 64M銆?/span>

 

2.2 濡備綍璁剧疆Memcached鐨勬墍鏈夊唴瀛樺ぇ灏?/span>

       Memcached鐨勯粯璁ょ殑鍐呭瓨澶у皬鏄?4M锛屾€庝箞璁剧疆锛熸瘮濡傝缃负128M锛屽彲浠ヤ娇鐢ㄥ涓嬪惎鍔ㄦ寚浠わ細

memcached -d  -m 128 -p 11211

       杩欐椂鍊欏湪浣跨敤鎸囦护鏌ョ湅锛?/span>

echo stats | nc 127.0.0.1 11211

       杩欐椂鍊檒imit_maxbytes = 134217728=2*67108864=2*64*1024*1024=128M

2.3 memcached鐨勫唴瀛樻槸濡備綍鍒嗛厤鐨勶紵

memcached閫氳繃璁剧疆-m鏉ュ垎閰嶆渶澶у唴瀛?/span>锛岄粯璁ゆ槸64MB锛屼絾鏄?/span>涓嶆槸涓€寮€濮嬪氨浼氱洿鎺ュ悜鎿嶄綔绯荤粺鐢宠-m璁剧疆鐨勫唴瀛?/span>;鐒跺悗灏嗗唴瀛樺垎鎴愬涓猵age锛屼竴涓猵age涓?MB锛屾瘡涓猵age閲岄潰鏈夊涓浐瀹氬ぇ灏忕殑鍐呭瓨鍧梒hunk锛屽叾澶у皬鏈€灏忎负96Bytes锛屾渶澶т负1MB锛岀敱澧為暱鍥犲瓙鏉ュ喅瀹氫腑闂村唴瀛樺潡鐨勫ぇ灏忥紝姣忕澶у皬鐨刢hunk瀵瑰簲涓€涓猻lab class銆傚綋鍏朵腑鐨勪竴涓ぇ灏忕殑鍐呭瓨鍧楁墍鐢宠鐨刾age娌℃湁绌洪棿浜嗭紝鍙互鐢宠澶氫竴涓ぇ灏忕殑鍐呭瓨鍧梡age銆傛墍浠ユ渶澶х殑涓€涓猭ey+value涓嶈兘瓒呰繃1MB銆傚唴瀛樺垎閰嶇瓥鐣ュ彨鍋歴lab allocation銆?/span>

2.4涓嶅悓鐨?page锛屽叾 slab-class 鍙兘鏄竴鏍风殑

       涓嶅悓鐨?page锛屽叾 slab-class 鍙兘鏄竴鏍风殑锛屾瘮濡傛墍鏈夌殑 item 閮藉皬浜?80 瀛楄妭锛屼竴鏃︾涓€涓?page 瀛樺偍婊′簡锛岄偅涔?Memcached 鍚敤绗簩涓?page 鐨勬椂鍊欙紝鍏朵粛鐒惰鎸囧畾涓?slab-class 2銆?/span>

BTW锛氭瘡涓猵age鏈€澶?M,鎵€鏈夌殑item鎬诲拰瓒呰繃1M涔嬪悗锛屽氨闇€瑕佸瓨鍌ㄥ埌slab class2

 

2.5 1M鐨処tem锛宻lab-class鑳藉瓨鍌ㄥ灏戜釜chunk?

       濡傛灉鏈変釜 item 鏄?1M锛岄偅涔堣繖涓?slab-class 鍙兘瀛樺偍 1 涓猚hunk銆?/span>

BTW锛歴lab-class鏄浉鍚屽ぇ灏忕殑chunk鐨勯泦鍚堬紝涓€涓猵age鐨勫ぇ灏忔槸1M锛屽鏋渃hunk 澶у皬鏄?96 瀛楄妭锛岄偅涔堝搴旂殑 page 鏈€澶氬彲浠ュ瓨鍌?10922 涓猚hunk锛屽鏋渃hunk澶у皬鏄?M,閭ｄ箞瀵瑰簲鐨刾age鏈€澶氬彲浠ュ瓨鍌?涓紝涔熷氨鏄鏋渋tem=1M,slb-class鐨勯泦鍚堜釜鏁板氨鏄?銆?/span>

涓夈€佹偀绾ゅ皬鑺?/span>

       杩欎竴鑺傜殑鐭ヨ瘑鐐癸紝閮芥尯閲嶈鐨勶紝杩樻槸闇€瑕佸師鏂囧ソ濂藉搧璇汇€?/span>

鎴戝氨鏄垜锛屾槸棰滆壊涓嶄竴鏍风殑鐑熺伀銆?br class="mq-387">鎴戝氨鏄垜锛屾槸涓庝紬涓嶅悓鐨勫皬鑻规灉銆?/code>

脿鎮熺┖瀛﹂櫌锛?span class="mq-391">https://t.cn/Rg3fKJD

瀛﹂櫌涓湁Spring Boot鐩稿叧鐨勮绋嬶紒鐐瑰嚮銆?/span>闃呰鍘熸枃銆嶈繘琛屾煡鐪嬶紒

SpringBoot瑙嗛锛歨ttps://t.cn/R3QepWG

Spring Cloud瑙嗛锛歨ttps://t.cn/R3QeRZc

SpringBoot Shiro瑙嗛锛歨ttps://t.cn/R3QDMbh

SpringBoot浜ゆ祦骞冲彴锛歨ttps://t.cn/R3QDhU0

SpringData鍜孞PA瑙嗛锛歨ttps://t.cn/R1pSojf

SpringSecurity5.0瑙嗛锛歨ttps://t.cn/EwlLjHh

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