将v8的内存管理配置为node.js进程的智能

Hit*_*pta 27 garbage-collection memory-management v8 node.js

我们在node.js上运行一个XMPP服务器,在一台大约3.8 GB RAM的机器上运行.以下是我们在调用节点时传递的命令行参数:/ opt/node/bin/node --max-old-space-size = 3000 --trace-gc --trace-gc-verbose main.js

但是,我们经常需要在此过程中看到超过10秒的gc暂停(有时多达1分钟gc暂停,我们的服务器除了运行GC之外什么都不做).当发生这种情况时,我们的进程是正常的内存消耗:大约1 GB的堆使用量.该过程有大约2 GB或可用空间,但该过程不使用它并花费一分钟尝试释放内存.

查看--trace-gc-verbose选项给出的gc跟踪,看起来大约2 GB的可用空间被标记为"大对象空间",并且没有使用,因为没有那么多大对象.虽然该过程迫切需要更多内存用于"旧指针"和"旧数据空间",但不使用来自"大对象空间"的这个空闲内存.

这是gc在其中一个时间内留下的痕迹,其中有一个长gc暂停:

    

91635809 ms: Mark-sweep 968.8 (1039.0) -> 958.5 (1038.0) MB, 1 / 410 ms (+ 2287 ms in 79 steps since start of marking, biggest step 140.227051 ms) [idle notification: finalize incremental] [GC in old space requested].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:      192, available:  8388416
Old pointers,       used: 633992112, available: 10460240, waste:        0
Old data space,     used: 315819248, available:   149776, waste:        0
Code space,         used:  5867936, available:  1271392, waste:        0
Map space,          used: 10257976, available:  6384072, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91636499 ms: Scavenge 965.5 (1038.0) -> 964.6 (1038.0) MB, 17 ms (+ 109 ms in 10 steps since last GC) [Runtime::PerformGC].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:    41256, available:  2055896
Old pointers,       used: 628458688, available: 15993664, waste:        0
Old data space,     used: 315821792, available:   147232, waste:        0
Code space,         used:  5904256, available:  1235072, waste:        0
Map space,          used: 10263072, available:  6378976, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91637979 ms: Scavenge 966.6 (1038.0) -> 964.7 (1038.0) MB, 1 ms (+ 1404 ms in 43 steps since last GC) [Runtime::PerformGC].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:    76736, available:  2020416
Old pointers,       used: 628458688, available: 15993664, waste:        0
Old data space,     used: 315845520, available:   123504, waste:        0
Code space,         used:  5980576, available:  1158752, waste:        0
Map space,          used: 10271416, available:  6370632, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91639088 ms: Mark-sweep 965.2 (1038.0) -> 935.8 (1038.0) MB, 1 / 369 ms (+ 2235 ms in 71 steps since start of marking, biggest step 69.053955 ms) [idle notification: finalize incremental] [GC in old space requested].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:      168, available:  2096984
Old pointers,       used: 641099768, available:  3352584, waste:        0
Old data space,     used: 315820152, available:   148872, waste:        0
Code space,         used:  5862976, available:  1276352, waste:        0
Map space,          used: 10256744, available:  6385304, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91640987 ms: Scavenge 966.4 (1038.0) -> 964.5 (1038.0) MB, 1 ms (+ 1275 ms in 36 steps since last GC) [allocation failure].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:   100944, available:  1996208
Old pointers,       used: 627957504, available: 16494848, waste:        0
Old data space,     used: 315830536, available:   138488, waste:        0
Code space,         used:  5951200, available:  1188128, waste:        0
Map space,          used: 10266376, available:  6375672, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91641560 ms: Scavenge 966.5 (1038.0) -> 964.8 (1038.0) MB, 2 ms (+ 481 ms in 29 steps since last GC) [Runtime::PerformGC].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:   180712, available:  1916440
Old pointers,       used: 627957504, available: 16494848, waste:        0
Old data space,     used: 315871432, available:    97592, waste:        0
Code space,         used:  6019392, available:  1119936, waste:        0
Map space,          used: 10269848, available:  6372200, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2123325184
91642589 ms: Mark-sweep 965.9 (1038.0) -> 947.7 (1038.0) MB, 1 / 371 ms (+ 2369 ms in 89 steps since start of marking, biggest step 67.302002 ms) [idle notification: finalize incremental] [GC in old space requested].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:      264, available:  2096888
Old pointers,       used: 639592840, available:  4859512, waste:        0
Old data space,     used: 315849408, available:   119616, waste:        0
Code space,         used:  5862976, available:  1276352, waste:        0
Map space,          used: 10257136, available:  6384912, waste:        0
Cell space,         used:   175936, available:   954304, waste:        0
Large object space, used: 51413600, available: 2123325184
91643688 ms: Scavenge 966.4 (1038.0) -> 964.6 (1038.0) MB, 5 ms (+ 356 ms in 21 steps since last GC) [Runtime::PerformGC].
Memory allocator,   used: 1088446464, available: 2124390400
New space,          used:   144088, available:  1953064
Old pointers,       used: 627748368, available: 16703984, waste:        0
Old data space,     used: 315864504, available:   104520, waste:        0
Code space,         used:  5990240, available:  1149088, waste:        0
Map space,          used: 10264248, available:  6377800, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2123325184
91645276 ms: Scavenge 966.5 (1038.0) -> 964.8 (1039.0) MB, 2 ms (+ 1520 ms in 46 steps since last GC) [allocation failure].
Memory allocator,   used: 1089495040, available: 2123341824
New space,          used:   108192, available:  1988960
Old pointers,       used: 627748368, available: 16703984, waste:        0
Old data space,     used: 315978760, available:  1022200, waste:        0
Code space,         used:  6039008, available:  1100320, waste:        0
Map space,          used: 10274216, available:  6367832, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2122276608
91645577 ms: Scavenge 966.6 (1039.0) -> 965.8 (1039.0) MB, 3 ms (+ 263 ms in 23 steps since last GC) [allocation failure].
Memory allocator,   used: 1089495040, available: 2123341824
New space,          used:   516168, available:  1580984
Old pointers,       used: 627843088, available: 16609264, waste:        0
Old data space,     used: 316550680, available:   450280, waste:        0
Code space,         used:  6039008, available:  1100320, waste:        0
Map space,          used: 10275280, available:  6366768, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2122276608
91645645 ms: Scavenge 967.3 (1039.0) -> 966.8 (1039.0) MB, 5 ms (+ 8 ms in 16 steps since last GC) [allocation failure].
Memory allocator,   used: 1089495040, available: 2123341824
New space,          used:  1012304, available:  3182000               
Old pointers,       used: 627968088, available: 16484264, waste:        0
Old data space,     used: 316947304, available:    53656, waste:        0
Code space,         used:  6039008, available:  1100320, waste:        0
Map space,          used: 10275280, available:  6366768, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2122276608
91645948 ms: Scavenge 969.8 (1039.0) -> 968.6 (1041.0) MB, 9 ms (+ 188 ms in 35 steps since last GC) [allocation failure].
Memory allocator,   used: 1091592192, available: 2121244672
New space,          used:  1032320, available:  3161984
Old pointers,       used: 628219008, available: 16233344, waste:        0
Old data space,     used: 318537928, available:   526904, waste:        0
Code space,         used:  6039264, available:  1100064, waste:        0
Map space,          used: 10276232, available:  6365816, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2120179456
91646093 ms: Scavenge 971.6 (1041.0) -> 970.5 (1042.0) MB, 13 ms (+ 36 ms in 30 steps since last GC) [Runtime::PerformGC].
Memory allocator,   used: 1092640768, available: 2120196096
New space,          used:  2044456, available:  6344152
Old pointers,       used: 628437424, available: 16014928, waste:        0
Old data space,     used: 319366376, available:   730392, waste:        0
Code space,         used:  6039264, available:  1100064, waste:        0
Map space,          used: 10276232, available:  6365816, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2119130880
91646306 ms: Scavenge 976.5 (1042.0) -> 974.7 (1044.0) MB, 1 / 14 ms (+ 114 ms in 67 steps since last GC) [allocation failure].
Memory allocator,   used: 1094737920, available: 2118098944
New space,          used:  2064112, available:  6324496
Old pointers,       used: 630440024, available: 14012328, waste:        0
Old data space,     used: 321653384, available:   507256, waste:        0
Code space,         used:  6055936, available:  1083392, waste:        0
Map space,          used: 10278192, available:  6363856, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2117033728
91646386 ms: Scavenge 980.6 (1044.0) -> 979.2 (1046.0) MB, 12 ms (+ 10 ms in 64 steps since last GC) [allocation failure].
Memory allocator,   used: 1096835072, available: 2116001792
New space,          used:  4127736, available: 12649480
Old pointers,       used: 631182984, available: 13269368, waste:        0
Old data space,     used: 323586008, available:   638504, waste:        0
Code space,         used:  6055936, available:  1083392, waste:        0
Map space,          used: 10278192, available:  6363856, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2114936576
Limited new space size due to high promotion rate: 1 MB
91646810 ms: Mark-sweep 979.2 (1046.0) -> 973.2 (1049.0) MB, 1 / 422 ms (+ 2500 ms in 303 steps since start of marking, biggest step 0.122070 ms) [StackGuard GC request] [GC in old space requested].
Memory allocator,   used: 1099980800, available: 2112856064
New space,          used:      192, available:  1048384
Old pointers,       used: 636894816, available:  9621408, waste:        0
Old data space,     used: 325256448, available:        0, waste:        0
Code space,         used:  5860928, available:  1278400, waste:        0
Map space,          used: 10257976, available:  6384072, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2111790848
91646825 ms: Scavenge 974.2 (1049.0) -> 979.0 (1049.0) MB, 7 ms [allocation failure].
Memory allocator,   used: 1099980800, available: 2112856064
New space,          used:   257960, available:   790616
Old pointers,       used: 635948464, available: 10567760, waste:        0
Old data space,     used: 325256448, available:        0, waste:        0
Code space,         used:  5873440, available:  1265888, waste:        0
Map space,          used: 10258536, available:  6383512, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2111790848
91646834 ms: Scavenge 979.7 (1049.0) -> 980.0 (1049.0) MB, 2 ms [allocation failure].
Memory allocator,   used: 1099980800, available: 2112856064
New space,          used:   257968, available:   790608
Old pointers,       used: 635671408, available: 10844816, waste:        0
Old data space,     used: 325256448, available:        0, waste:        0
Code space,         used:  5873440, available:  1265888, waste:        0
Map space,          used: 10258536, available:  6383512, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2111790848
91646842 ms: Scavenge 980.7 (1049.0) -> 980.6 (1049.0) MB, 2 ms [allocation failure].
Memory allocator,   used: 1099980800, available: 2112856064
New space,          used:   257960, available:   790616
Old pointers,       used: 635493872, available: 11022352, waste:        0
Old data space,     used: 325256448, available:        0, waste:        0
Code space,         used:  5873440, available:  1265888, waste:        0
Map space,          used: 10258536, available:  6383512, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2111790848
91646849 ms: Scavenge 981.3 (1049.0) -> 981.2 (1049.0) MB, 1 ms [allocation failure].
Memory allocator,   used: 1099980800, available: 2112856064
New space,          used:   257968, available:   790608
Old pointers,       used: 635981640, available: 10534584, waste:        0
Old data space,     used: 325256448, available:        0, waste:        0
Code space,         used:  5873440, available:  1265888, waste:        0
Map space,          used: 10258536, available:  6383512, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2111790848
91646863 ms: Scavenge 981.9 (1049.0) -> 981.6 (1051.0) MB, 1 ms [allocation failure].
Memory allocator,   used: 1102077952, available: 2110758912
New space,          used:   257960, available:   790616
Old pointers,       used: 637013288, available: 10534872, waste:        0
Old data space,     used: 326288384, available:        0, waste:        0
Code space,         used:  5873440, available:  1265888, waste:        0
Map space,          used: 10258536, available:  6383512, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2109693696
91651639 ms: Mark-sweep 981.6 (1051.0) -> 924.7 (1051.0) MB, 1 / 4775 ms [last resort gc].
Memory allocator,   used: 1102077952, available: 2110758912
New space,          used:       96, available:  1048480
Old pointers,       used: 626794192, available: 20753968, waste:        0
Old data space,     used: 275760200, available: 50528184, waste:        0
Code space,         used:  6182208, available:   957120, waste:        0
Map space,          used: 10257808, available:  6384240, waste:        0
Cell space,         used:   176192, available:   954048, waste:        0
Large object space, used: 51413600, available: 2109693696
91663655 ms: Mark-sweep 924.7 (1051.0) -> 924.7 (1050.0) MB, 1 / 12015 ms [last resort gc].
Memory allocator,   used: 1101029376, available: 2111807488
New space,          used:        0, available:  1048576
Old pointers,       used: 626169464, available: 21378696, waste:        0
Old data space,     used: 275759960, available: 49496488, waste:        0
Code space,         used:  5850624, available:  1288704, waste:        0
Map space,          used: 10257808, available:  6384240, waste:                 


是否有任何调整可以更好地配置v8的内存管理?关于什么可能有帮助的任何想法?

use*_*109 23

我认为这是V8的限制.它在64位计算机上不使用超过1.7 GB的RAM.常见问题引用:

目前,默认情况下,v8在32位系统上的内存限制为512mb,在64位系统上的内存限制为1GB.通过将--max-old-space-size设置为最大~1gb(32位)和~1.7gb(64位)可以提高限制,但建议您将单个进程分成几个工作程序如果你达到内存限制.

因此,在此之后您将达到最大内存限制,并且由于垃圾收集而暂停10秒是一个很大的担忧.您应该考虑定期/在空闲时运行垃圾收集器,以避免达到限制并面临长时间延迟.

您可以传递以帮助这种情况的参数是:(查看此博客)

  • --nouse-idle-notification 这可以防止GC持续运行
  • --expose-gc 这将允许您从代码中运行GC.

最重要的是调试代码以消除内存泄漏.使用这些包在您的代码中找到它们:

  • 我可以使用节点版本0.10.33以及0.12.4确认短划线工作.但要注意的一件事是参数必须在脚本之前传递,所以`node --max-old-space-size = 8192 script.js`而不是`node script.js --max-old-空间的大小= 8192` (15认同)
  • 关于下划线v.破折号:https://nodejs.org/api/cli.html#cli_v8_options说"_Note_:V8选项允许单词用短划线(`-`)或下划线(`_`)分隔." ..所以使用破折号是*不*"错误". (5认同)