{"id":476390,"date":"2023-08-09T07:28:31","date_gmt":"2023-08-09T07:28:31","guid":{"rendered":""},"modified":"2023-09-05T11:12:37","modified_gmt":"2023-09-05T11:12:37","slug":"concurrency-control","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/vn\/wiki\/concurrency-control\/","title":{"rendered":"\u0110\u1ed3ng th\u1eddi ki\u1ec3m so\u00e1t"},"content":{"rendered":"<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u00e0 m\u1ed9t kh\u00eda c\u1ea1nh quan tr\u1ecdng c\u1ee7a c\u00e1c h\u1ec7 th\u1ed1ng m\u00e1y t\u00ednh hi\u1ec7n \u0111\u1ea1i, \u0111\u1eb7c bi\u1ec7t l\u00e0 trong b\u1ed1i c\u1ea3nh m\u00e1y ch\u1ee7 proxy. \u0110\u00f3 l\u00e0 m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 qu\u1ea3n l\u00fd quy\u1ec1n truy c\u1eadp \u0111\u1ed3ng th\u1eddi v\u00e0o c\u00e1c t\u00e0i nguy\u00ean \u0111\u01b0\u1ee3c chia s\u1ebb, \u0111\u1ea3m b\u1ea3o r\u1eb1ng nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng ho\u1eb7c quy tr\u00ecnh c\u00f3 th\u1ec3 t\u01b0\u01a1ng t\u00e1c v\u1edbi ch\u00fang m\u00e0 kh\u00f4ng g\u00e2y ra xung \u0111\u1ed9t ho\u1eb7c m\u00e2u thu\u1eabn d\u1eef li\u1ec7u. M\u1ee5c ti\u00eau ch\u00ednh c\u1ee7a ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u00e0 duy tr\u00ec t\u00ednh to\u00e0n v\u1eb9n v\u00e0 nh\u1ea5t qu\u00e1n c\u1ee7a d\u1eef li\u1ec7u trong khi t\u1ed1i \u0111a h\u00f3a hi\u1ec7u su\u1ea5t v\u00e0 hi\u1ec7u qu\u1ea3.<\/p>\n<h2>L\u1ecbch s\u1eed ngu\u1ed3n g\u1ed1c c\u1ee7a Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi v\u00e0 l\u1ea7n \u0111\u1ea7u ti\u00ean \u0111\u1ec1 c\u1eadp \u0111\u1ebfn n\u00f3<\/h2>\n<p>Kh\u00e1i ni\u1ec7m ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi c\u00f3 t\u1eeb nh\u1eefng ng\u00e0y \u0111\u1ea7u c\u1ee7a \u0111i\u1ec7n to\u00e1n khi c\u00e1c h\u1ec7 th\u1ed1ng nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng tr\u1edf n\u00ean ph\u1ed5 bi\u1ebfn. Vi\u1ec7c \u0111\u1ec1 c\u1eadp \u0111\u1ebfn ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u1ea7n \u0111\u1ea7u ti\u00ean c\u00f3 th\u1ec3 b\u1eaft ngu\u1ed3n t\u1eeb nh\u1eefng n\u0103m 1960 v\u00e0 1970 khi c\u01a1 s\u1edf d\u1eef li\u1ec7u v\u00e0 h\u1ec7 th\u1ed1ng x\u1eed l\u00fd giao d\u1ecbch b\u1eaft \u0111\u1ea7u tr\u1edf n\u00ean ph\u1ed5 bi\u1ebfn. Trong th\u1eddi gian n\u00e0y, nhu c\u1ea7u x\u1eed l\u00fd c\u00e1c giao d\u1ecbch \u0111\u1ed3ng th\u1eddi m\u00e0 kh\u00f4ng b\u1ecb can thi\u1ec7p n\u1ed5i l\u00ean nh\u01b0 m\u1ed9t th\u00e1ch th\u1ee9c quan tr\u1ecdng.<\/p>\n<h2>Th\u00f4ng tin chi ti\u1ebft v\u1ec1 Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi gi\u1ea3i quy\u1ebft v\u1ea5n \u0111\u1ec1 nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng ho\u1eb7c quy tr\u00ecnh c\u1ed1 g\u1eafng truy c\u1eadp c\u00e1c t\u00e0i nguy\u00ean \u0111\u01b0\u1ee3c chia s\u1ebb c\u00f9ng m\u1ed9t l\u00fac. Trong tr\u01b0\u1eddng h\u1ee3p kh\u00f4ng c\u00f3 c\u01a1 ch\u1ebf ki\u1ec3m so\u00e1t th\u00edch h\u1ee3p, c\u00e1c ho\u1ea1t \u0111\u1ed9ng \u0111\u1ed3ng th\u1eddi c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn nhi\u1ec1u v\u1ea5n \u0111\u1ec1 kh\u00e1c nhau nh\u01b0:<\/p>\n<ul>\n<li>\n<p><strong>C\u1eadp nh\u1eadt b\u1ecb m\u1ea5t:<\/strong> Khi hai ho\u1eb7c nhi\u1ec1u giao d\u1ecbch c\u1ed1 g\u1eafng c\u1eadp nh\u1eadt c\u00f9ng m\u1ed9t t\u00e0i nguy\u00ean c\u00f9ng m\u1ed9t l\u00fac, m\u1ed9t b\u1ea3n c\u1eadp nh\u1eadt c\u00f3 th\u1ec3 b\u1ecb m\u1ea5t, d\u1eabn \u0111\u1ebfn d\u1eef li\u1ec7u kh\u00f4ng nh\u1ea5t qu\u00e1n.<\/p>\n<\/li>\n<li>\n<p><strong>\u0110\u1ecdc b\u1ea9n:<\/strong> M\u1ed9t giao d\u1ecbch \u0111\u1ecdc d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c s\u1eeda \u0111\u1ed5i b\u1edfi m\u1ed9t giao d\u1ecbch kh\u00e1c ch\u01b0a \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n, d\u1eabn \u0111\u1ebfn vi\u1ec7c truy xu\u1ea5t th\u00f4ng tin kh\u00f4ng ch\u00ednh x\u00e1c.<\/p>\n<\/li>\n<li>\n<p><strong>S\u1ed1 l\u1ea7n \u0111\u1ecdc kh\u00f4ng th\u1ec3 l\u1eb7p l\u1ea1i:<\/strong> Khi m\u1ed9t giao d\u1ecbch \u0111\u1ecdc c\u00f9ng m\u1ed9t d\u1eef li\u1ec7u nhi\u1ec1u l\u1ea7n trong qu\u00e1 tr\u00ecnh th\u1ef1c hi\u1ec7n, n\u00f3 c\u00f3 th\u1ec3 t\u00ecm th\u1ea5y c\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau do c\u00e1c giao d\u1ecbch kh\u00e1c th\u1ef1c hi\u1ec7n c\u1eadp nh\u1eadt.<\/p>\n<\/li>\n<li>\n<p><strong>\u0110\u1ecdc \u1ea3o:<\/strong> M\u1ed9t giao d\u1ecbch \u0111\u1ecdc m\u1ed9t t\u1eadp h\u1ee3p d\u1eef li\u1ec7u v\u00e0 trong qu\u00e1 tr\u00ecnh th\u1ef1c hi\u1ec7n, m\u1ed9t giao d\u1ecbch kh\u00e1c s\u1ebd ch\u00e8n ho\u1eb7c x\u00f3a c\u00e1c h\u00e0ng, khi\u1ebfn giao d\u1ecbch \u0111\u1ea7u ti\u00ean nh\u1eadn th\u1ea5y c\u00e1c b\u1ea3n ghi b\u1ed5 sung ho\u1eb7c b\u1ecb thi\u1ebfu.<\/p>\n<\/li>\n<\/ul>\n<h2>C\u1ea5u tr\u00fac b\u00ean trong c\u1ee7a Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi. C\u00e1ch th\u1ee9c ho\u1ea1t \u0111\u1ed9ng c\u1ee7a Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi s\u1eed d\u1ee5ng nhi\u1ec1u k\u1ef9 thu\u1eadt kh\u00e1c nhau \u0111\u1ec3 qu\u1ea3n l\u00fd truy c\u1eadp \u0111\u1ed3ng th\u1eddi m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3. Nh\u1eefng k\u1ef9 thu\u1eadt n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c chia th\u00e0nh hai lo\u1ea1i:<\/p>\n<ol>\n<li>\n<p><strong>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi bi quan:<\/strong> Theo c\u00e1ch ti\u1ebfp c\u1eadn n\u00e0y, c\u01a1 ch\u1ebf d\u1ef1a tr\u00ean kh\u00f3a \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ng\u0103n ng\u01b0\u1eddi d\u00f9ng kh\u00e1c truy c\u1eadp v\u00e0o t\u00e0i nguy\u00ean trong khi t\u00e0i nguy\u00ean \u0111\u00f3 \u0111ang \u0111\u01b0\u1ee3c giao d\u1ecbch s\u1eed d\u1ee5ng. C\u00e1ch ti\u1ebfp c\u1eadn n\u00e0y mang t\u00ednh \u201cbi quan\u201d v\u00ec n\u00f3 cho r\u1eb1ng xung \u0111\u1ed9t c\u00f3 th\u1ec3 x\u1ea3y ra v\u00e0 th\u1ef1c hi\u1ec7n c\u00e1c bi\u1ec7n ph\u00e1p ph\u00f2ng ng\u1eeba \u0111\u1ec3 ng\u0103n ch\u1eb7n ch\u00fang. C\u00e1c lo\u1ea1i kh\u00f3a ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n<ul>\n<li>\n<p><strong>Kh\u00f3a chia s\u1ebb (S-lock):<\/strong> Cho ph\u00e9p nhi\u1ec1u giao d\u1ecbch \u0111\u1ecdc t\u00e0i nguy\u00ean \u0111\u1ed3ng th\u1eddi nh\u01b0ng ng\u0103n ch\u1eb7n quy\u1ec1n truy c\u1eadp ghi.<\/p>\n<\/li>\n<li>\n<p><strong>Kh\u00f3a \u0111\u1ed9c quy\u1ec1n (X-lock):<\/strong> \u0110\u1ea3m b\u1ea3o quy\u1ec1n truy c\u1eadp \u0111\u1ed9c quy\u1ec1n, ng\u0103n ch\u1eb7n m\u1ecdi giao d\u1ecbch kh\u00e1c \u0111\u1ecdc ho\u1eb7c ghi t\u00e0i nguy\u00ean.<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<p><strong>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u1ea1c quan:<\/strong> C\u00e1ch ti\u1ebfp c\u1eadn n\u00e0y gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng xung \u0111\u1ed9t kh\u00f4ng x\u1ea3y ra th\u01b0\u1eddng xuy\u00ean v\u00e0 kh\u00f4ng s\u1eed d\u1ee5ng kh\u00f3a. Thay v\u00e0o \u0111\u00f3, n\u00f3 cho ph\u00e9p c\u00e1c giao d\u1ecbch \u0111\u01b0\u1ee3c ti\u1ebfn h\u00e0nh m\u00e0 kh\u00f4ng b\u1ecb ch\u1eb7n. Tr\u01b0\u1edbc khi cam k\u1ebft, h\u1ec7 th\u1ed1ng s\u1ebd ki\u1ec3m tra xung \u0111\u1ed9t v\u00e0 \u0111\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n c\u1ee7a d\u1eef li\u1ec7u. N\u1ebfu ph\u00e1t hi\u1ec7n xung \u0111\u1ed9t, giao d\u1ecbch s\u1ebd \u0111\u01b0\u1ee3c kh\u00f4i ph\u1ee5c v\u00e0 qu\u00e1 tr\u00ecnh n\u00e0y \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i cho \u0111\u1ebfn khi th\u00e0nh c\u00f4ng.<\/p>\n<\/li>\n<\/ol>\n<h2>Ph\u00e2n t\u00edch c\u00e1c t\u00ednh n\u0103ng ch\u00ednh c\u1ee7a Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>C\u00e1c t\u00ednh n\u0103ng ch\u00ednh c\u1ee7a Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi bao g\u1ed3m:<\/p>\n<ul>\n<li>\n<p><strong>S\u1ef1 c\u00e1ch ly:<\/strong> \u0110\u1ea3m b\u1ea3o r\u1eb1ng m\u1ed7i giao d\u1ecbch \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n t\u00e1ch bi\u1ec7t v\u1edbi c\u00e1c giao d\u1ecbch kh\u00e1c \u0111\u1ec3 ng\u0103n ch\u1eb7n s\u1ef1 can thi\u1ec7p v\u00e0 duy tr\u00ec t\u00ednh nh\u1ea5t qu\u00e1n.<\/p>\n<\/li>\n<li>\n<p><strong>\u0110\u1ed9 chi ti\u1ebft c\u1ee7a kh\u00f3a:<\/strong> X\u00e1c \u0111\u1ecbnh k\u00edch th\u01b0\u1edbc v\u00e0 ph\u1ea1m vi c\u1ee7a kh\u00f3a \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c s\u1ef1 c\u00e2n b\u1eb1ng gi\u1eefa \u0111\u1ed3ng th\u1eddi v\u00e0 tranh ch\u1ea5p t\u00e0i nguy\u00ean.<\/p>\n<\/li>\n<li>\n<p><strong>X\u1eed l\u00fd b\u1ebf t\u1eafc:<\/strong> Tri\u1ec3n khai c\u01a1 ch\u1ebf ph\u00e1t hi\u1ec7n v\u00e0 gi\u1ea3i quy\u1ebft c\u00e1c b\u1ebf t\u1eafc x\u1ea3y ra khi c\u00e1c giao d\u1ecbch \u0111ang ch\u1edd nhau gi\u1ea3i ph\u00f3ng kh\u00f3a.<\/p>\n<\/li>\n<li>\n<p><strong>\u0110\u1ed9 b\u1ec1n giao d\u1ecbch:<\/strong> \u0110\u1ea3m b\u1ea3o r\u1eb1ng m\u1ed9t khi giao d\u1ecbch \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n, nh\u1eefng thay \u0111\u1ed5i c\u1ee7a n\u00f3 l\u00e0 v\u0129nh vi\u1ec5n v\u00e0 kh\u00f4ng b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi l\u1ed7i h\u1ec7 th\u1ed1ng.<\/p>\n<\/li>\n<li>\n<p><strong>Thu\u1eadt to\u00e1n ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi:<\/strong> C\u00e1c thu\u1eadt to\u00e1n kh\u00e1c nhau nh\u01b0 Kh\u00f3a hai pha (2PL), Th\u1ee9 t\u1ef1 d\u1ea5u th\u1eddi gian v\u00e0 C\u00e1ch ly \u1ea3nh ch\u1ee5p nhanh c\u00f3 th\u1ec3 n\u1ed1i ti\u1ebfp (SSI) \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 qu\u1ea3n l\u00fd quy\u1ec1n truy c\u1eadp \u0111\u1ed3ng th\u1eddi.<\/p>\n<\/li>\n<\/ul>\n<h2>C\u00e1c lo\u1ea1i ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i d\u1ef1a tr\u00ean ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn c\u1ee7a ch\u00fang:<\/p>\n<table>\n<thead>\n<tr>\n<th>Ki\u1ec3u<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi bi quan<\/td>\n<td>S\u1eed d\u1ee5ng c\u00e1c kh\u00f3a \u0111\u1ec3 ng\u0103n ch\u1eb7n truy c\u1eadp \u0111\u1ed3ng th\u1eddi v\u00e0o t\u00e0i nguy\u00ean.<\/td>\n<\/tr>\n<tr>\n<td>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u1ea1c quan<\/td>\n<td>Cho ph\u00e9p truy c\u1eadp \u0111\u1ed3ng th\u1eddi v\u00e0 ki\u1ec3m tra xung \u0111\u1ed9t tr\u01b0\u1edbc khi cam k\u1ebft.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>C\u00e1ch s\u1eed d\u1ee5ng Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi, c\u00e1c v\u1ea5n \u0111\u1ec1 v\u00e0 gi\u1ea3i ph\u00e1p li\u00ean quan \u0111\u1ebfn vi\u1ec7c s\u1eed d\u1ee5ng<\/h2>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi l\u00e0 \u0111i\u1ec1u c\u1ea7n thi\u1ebft trong nhi\u1ec1u t\u00ecnh hu\u1ed1ng kh\u00e1c nhau, bao g\u1ed3m:<\/p>\n<ul>\n<li>\n<p><strong>H\u1ec7 th\u1ed1ng Qu\u1ea3n l\u00fd D\u1eef li\u1ec7u:<\/strong> \u0110\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n v\u00e0 to\u00e0n v\u1eb9n d\u1eef li\u1ec7u trong m\u00f4i tr\u01b0\u1eddng c\u01a1 s\u1edf d\u1eef li\u1ec7u nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng.<\/p>\n<\/li>\n<li>\n<p><strong>M\u00e1y ch\u1ee7 proxy:<\/strong> Qu\u1ea3n l\u00fd c\u00e1c y\u00eau c\u1ea7u \u0111\u1ed3ng th\u1eddi t\u1eeb nhi\u1ec1u kh\u00e1ch h\u00e0ng \u0111\u1ec3 cung c\u1ea5p d\u1ecbch v\u1ee5 hi\u1ec7u qu\u1ea3 v\u00e0 \u0111\u00e1ng tin c\u1eady.<\/p>\n<\/li>\n<\/ul>\n<p>C\u00e1c v\u1ea5n \u0111\u1ec1 li\u00ean quan \u0111\u1ebfn ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi bao g\u1ed3m:<\/p>\n<ul>\n<li>\n<p><strong>Chi ph\u00ed hi\u1ec7u su\u1ea5t:<\/strong> C\u00e1ch ti\u1ebfp c\u1eadn d\u1ef1a tr\u00ean kh\u00f3a c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn tranh ch\u1ea5p v\u00e0 gi\u1ea3m hi\u1ec7u su\u1ea5t.<\/p>\n<\/li>\n<li>\n<p><strong>B\u1ebf t\u1eafc:<\/strong> C\u00e1c giao d\u1ecbch ch\u1edd kh\u00f3a c\u1ee7a nhau c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn t\u00ecnh tr\u1ea1ng b\u1ebf t\u1eafc.<\/p>\n<\/li>\n<\/ul>\n<p>\u0110\u1ec3 gi\u1ea3i quy\u1ebft nh\u1eefng v\u1ea5n \u0111\u1ec1 n\u00e0y, c\u00e1c gi\u1ea3i ph\u00e1p nh\u01b0 thu\u1eadt to\u00e1n ph\u00e1t hi\u1ec7n v\u00e0 gi\u1ea3i quy\u1ebft b\u1ebf t\u1eafc, t\u1ed1i \u01b0u h\u00f3a qu\u1ea3n l\u00fd kh\u00f3a v\u00e0 tinh ch\u1ec9nh c\u00e1c tham s\u1ed1 ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng.<\/p>\n<h2>C\u00e1c \u0111\u1eb7c \u0111i\u1ec3m ch\u00ednh v\u00e0 so s\u00e1nh kh\u00e1c v\u1edbi c\u00e1c thu\u1eadt ng\u1eef t\u01b0\u01a1ng t\u1ef1<\/h2>\n<table>\n<thead>\n<tr>\n<th>\u0111\u1eb7c tr\u01b0ng<\/th>\n<th>\u0110\u1ed3ng th\u1eddi ki\u1ec3m so\u00e1t<\/th>\n<th>S\u1ef1 song song<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>M\u1ee5c \u0111\u00edch<\/td>\n<td>Qu\u1ea3n l\u00fd truy c\u1eadp \u0111\u1ed3ng th\u1eddi<\/td>\n<td>Th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi<\/td>\n<\/tr>\n<tr>\n<td>T\u1eadp trung<\/td>\n<td>T\u00ednh nh\u1ea5t qu\u00e1n c\u1ee7a d\u1eef li\u1ec7u<\/td>\n<td>Hi\u1ec7u su\u1ea5t n\u00e2ng cao<\/td>\n<\/tr>\n<tr>\n<td>C\u00e1ch s\u1eed d\u1ee5ng<\/td>\n<td>C\u01a1 s\u1edf d\u1eef li\u1ec7u, m\u00e1y ch\u1ee7 proxy<\/td>\n<td>C\u00e1c t\u00e1c v\u1ee5 s\u1eed d\u1ee5ng nhi\u1ec1u CPU<\/td>\n<\/tr>\n<tr>\n<td>C\u01a1 ch\u1ebf ch\u00ednh<\/td>\n<td>Kh\u00f3a, \u0111\u1eb7t h\u00e0ng d\u1ea5u th\u1eddi gian<\/td>\n<td>T\u00e1ch lu\u1ed3ng v\u00e0 ti\u1ebfn tr\u00ecnh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>C\u00e1c quan \u0111i\u1ec3m v\u00e0 c\u00f4ng ngh\u1ec7 c\u1ee7a t\u01b0\u01a1ng lai li\u00ean quan \u0111\u1ebfn Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>Khi c\u00f4ng ngh\u1ec7 ph\u00e1t tri\u1ec3n, c\u00e1c k\u1ef9 thu\u1eadt v\u00e0 ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn m\u1edbi \u0111\u1ec3 ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi s\u1ebd ti\u1ebfp t\u1ee5c xu\u1ea5t hi\u1ec7n. M\u1ed9t s\u1ed1 ph\u00e1t tri\u1ec3n ti\u1ec1m n\u0103ng trong t\u01b0\u01a1ng lai bao g\u1ed3m:<\/p>\n<ul>\n<li>\n<p><strong>Thu\u1eadt to\u00e1n kh\u00f4ng kh\u00f3a n\u00e2ng cao:<\/strong> Nghi\u00ean c\u1ee9u v\u00e0 ph\u00e1t tri\u1ec3n c\u00e1c thu\u1eadt to\u00e1n lock-free v\u00e0 wait-free \u0111\u1ec3 gi\u1ea3m thi\u1ec3u tranh ch\u1ea5p v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t.<\/p>\n<\/li>\n<li>\n<p><strong>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi ph\u00e2n t\u00e1n:<\/strong> Qu\u1ea3n l\u00fd \u0111\u1ed3ng th\u1eddi trong c\u00e1c h\u1ec7 th\u1ed1ng ph\u00e2n t\u00e1n v\u00e0 m\u00f4i tr\u01b0\u1eddng \u0111\u00e1m m\u00e2y \u0111\u1ec3 x\u1eed l\u00fd c\u00e1c th\u00e1ch th\u1ee9c v\u1ec1 kh\u1ea3 n\u0103ng m\u1edf r\u1ed9ng.<\/p>\n<\/li>\n<li>\n<p><strong>T\u00edch h\u1ee3p h\u1ecdc m\u00e1y:<\/strong> S\u1eed d\u1ee5ng c\u00e1c m\u00f4 h\u00ecnh h\u1ecdc m\u00e1y \u0111\u1ec3 d\u1ef1 \u0111o\u00e1n v\u00e0 t\u1ed1i \u01b0u h\u00f3a c\u00e1c c\u01a1 ch\u1ebf ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi d\u1ef1a tr\u00ean kh\u1ed1i l\u01b0\u1ee3ng c\u00f4ng vi\u1ec7c v\u00e0 ki\u1ec3u s\u1eed d\u1ee5ng t\u00e0i nguy\u00ean.<\/p>\n<\/li>\n<\/ul>\n<h2>C\u00e1ch s\u1eed d\u1ee5ng ho\u1eb7c li\u00ean k\u1ebft m\u00e1y ch\u1ee7 proxy v\u1edbi Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi<\/h2>\n<p>M\u00e1y ch\u1ee7 proxy \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c qu\u1ea3n l\u00fd v\u00e0 ph\u00e2n ph\u1ed1i c\u00e1c y\u00eau c\u1ea7u c\u1ee7a m\u00e1y kh\u00e1ch \u0111\u1ebfn m\u00e1y ch\u1ee7 ph\u1ee5 tr\u1ee3, \u0111\u00f3ng vai tr\u00f2 trung gian gi\u1eefa m\u00e1y kh\u00e1ch v\u00e0 t\u00e0i nguy\u00ean. B\u1eb1ng c\u00e1ch tri\u1ec3n khai c\u00e1c c\u01a1 ch\u1ebf ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi, m\u00e1y ch\u1ee7 proxy c\u00f3 th\u1ec3 x\u1eed l\u00fd \u0111\u1ed3ng th\u1eddi c\u00e1c y\u00eau c\u1ea7u c\u1ee7a kh\u00e1ch h\u00e0ng m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3 \u0111\u1ed3ng th\u1eddi \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n c\u1ee7a d\u1eef li\u1ec7u v\u00e0 ng\u0103n ch\u1eb7n s\u1ef1 kh\u00f4ng nh\u1ea5t qu\u00e1n c\u1ee7a d\u1eef li\u1ec7u.<\/p>\n<p>Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi trong m\u00e1y ch\u1ee7 proxy gi\u00fap:<\/p>\n<ul>\n<li>\n<p>Ng\u0103n ch\u1eb7n xung \u0111\u1ed9t khi nhi\u1ec1u kh\u00e1ch h\u00e0ng y\u00eau c\u1ea7u c\u00f9ng m\u1ed9t t\u00e0i nguy\u00ean c\u00f9ng m\u1ed9t l\u00fac.<\/p>\n<\/li>\n<li>\n<p>T\u1ed1i \u01b0u h\u00f3a vi\u1ec7c s\u1eed d\u1ee5ng t\u00e0i nguy\u00ean b\u1eb1ng c\u00e1ch qu\u1ea3n l\u00fd hi\u1ec7u qu\u1ea3 c\u00e1c y\u00eau c\u1ea7u \u0111\u1ed3ng th\u1eddi.<\/p>\n<\/li>\n<li>\n<p>N\u00e2ng cao hi\u1ec7u su\u1ea5t v\u00e0 kh\u1ea3 n\u0103ng \u0111\u00e1p \u1ee9ng c\u1ee7a h\u1ec7 th\u1ed1ng t\u1ed5ng th\u1ec3.<\/p>\n<\/li>\n<\/ul>\n<h2>Li\u00ean k\u1ebft li\u00ean quan<\/h2>\n<p>\u0110\u1ec3 bi\u1ebft th\u00eam th\u00f4ng tin v\u1ec1 Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi, b\u1ea1n c\u00f3 th\u1ec3 kh\u00e1m ph\u00e1 c\u00e1c t\u00e0i nguy\u00ean sau:<\/p>\n<ol>\n<li><a href=\"https:\/\/en.wikipedia.org\/wiki\/Concurrency_control\" target=\"_new\" rel=\"noopener nofollow\">Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi trong c\u01a1 s\u1edf d\u1eef li\u1ec7u - Wikipedia<\/a><\/li>\n<li><a href=\"https:\/\/www.tutorialspoint.com\/dbms\/dbms_concurrency_control.htm\" target=\"_new\" rel=\"noopener nofollow\">K\u1ef9 thu\u1eadt ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi \u2013 Tutorialspoint<\/a><\/li>\n<li><a href=\"https:\/\/www.oracle.com\/technical-resources\/articles\/database\/transaction-management-cdc.html\" target=\"_new\" rel=\"noopener nofollow\">H\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n v\u1ec1 ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi trong h\u1ec7 th\u1ed1ng c\u01a1 s\u1edf d\u1eef li\u1ec7u \u2013 Oracle<\/a><\/li>\n<li><a href=\"https:\/\/dl.acm.org\/doi\/10.1145\/3297858.3304027\" target=\"_new\" rel=\"noopener nofollow\">Ki\u1ec3m so\u00e1t \u0111\u1ed3ng th\u1eddi trong m\u00e1y ch\u1ee7 proxy \u2013 Th\u01b0 vi\u1ec7n s\u1ed1 ACM<\/a><\/li>\n<\/ol>","protected":false},"featured_media":476391,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-476390","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about <mark>Concurrency Control: Managing Simultaneous Access for Efficient Proxy Server Operations<\/mark>","faq_items":[{"question":"What is Concurrency Control?","answer":"<p>Concurrency control is a crucial aspect of modern computing systems that manages simultaneous access to shared resources. It ensures that multiple users or processes can interact with these resources without causing conflicts or data inconsistencies. The primary goal of concurrency control is to maintain data integrity and consistency while optimizing performance and efficiency.<\/p>"},{"question":"How does Concurrency Control work?","answer":"<p>Concurrency control employs various techniques to manage concurrent access effectively. There are two main approaches:<\/p><ol><li><p>Pessimistic Concurrency Control: This approach uses lock-based mechanisms to prevent other users from accessing a resource while it is being used by a transaction. Lock types, such as shared and exclusive locks, help regulate access.<\/p><\/li><li><p>Optimistic Concurrency Control: In this approach, transactions proceed without blocking, and before committing, the system checks for conflicts to ensure data consistency. If a conflict is detected, the transaction is rolled back and repeated until successful.<\/p><\/li><\/ol>"},{"question":"Why is Concurrency Control important for Proxy Servers?","answer":"<p>Concurrency control is crucial for proxy servers as they act as intermediaries between clients and backend servers, handling multiple client requests simultaneously. Implementing concurrency control mechanisms allows proxy servers to efficiently manage these requests while ensuring data integrity and preventing conflicts. It optimizes resource utilization, enhances performance, and maintains system responsiveness.<\/p>"},{"question":"What are the common issues related to Concurrency Control?","answer":"<p>Common issues related to concurrency control include:<\/p><ol><li><p>Performance Overhead: Lock-based approaches may lead to contention, reducing system performance.<\/p><\/li><li><p>Deadlocks: Transactions waiting for each other's locks can result in deadlock situations where they are unable to proceed.<\/p><\/li><\/ol>"},{"question":"What are the future perspectives and technologies related to Concurrency Control?","answer":"<p>The future of concurrency control is likely to see developments such as:<\/p><ol><li><p>Advanced Lock-Free Algorithms: Research and development of lock-free and wait-free algorithms to minimize contention and improve performance.<\/p><\/li><li><p>Distributed Concurrency Control: Managing concurrency in distributed systems and cloud environments to handle scalability challenges.<\/p><\/li><li><p>Machine Learning Integration: Utilizing machine learning models to predict and optimize concurrency control mechanisms based on workloads and resource usage patterns.<\/p><\/li><\/ol>"},{"question":"How are Concurrency Control and Parallelism different?","answer":"<p>Concurrency control and parallelism serve different purposes:<\/p><ul><li><p>Concurrency Control: Focuses on managing concurrent access to resources to maintain data consistency in multi-user environments like databases and proxy servers.<\/p><\/li><li><p>Parallelism: Aims to achieve enhanced performance by simultaneously executing multiple CPU-intensive tasks.<\/p><\/li><\/ul>"},{"question":"Where can I find more information about Concurrency Control?","answer":"<p>For more in-depth information about Concurrency Control, you can explore the following resources:<\/p><ol><li><a href=\"https:\/\/en.wikipedia.org\/wiki\/Concurrency_control\" target=\"_new\">Concurrency Control in Databases - Wikipedia<\/a><\/li><li><a href=\"https:\/\/www.tutorialspoint.com\/dbms\/dbms_concurrency_control.htm\" target=\"_new\">Concurrency Control Techniques - Tutorialspoint<\/a><\/li><li><a href=\"https:\/\/www.oracle.com\/technical-resources\/articles\/database\/transaction-management-cdc.html\" target=\"_new\">A Comprehensive Guide to Concurrency Control in Database Systems - Oracle<\/a><\/li><li><a href=\"https:\/\/dl.acm.org\/doi\/10.1145\/3297858.3304027\" target=\"_new\">Concurrency Control in Proxy Servers - ACM Digital Library<\/a><\/li><\/ol>"}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476390","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476390\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media\/476391"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media?parent=476390"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}