一次偶然间，发现测试环境iis站点内存突然间暴增，平常都是300M，这次一下子暴增到8g 于是就开始了接下来的分析
发现Dictionary居然有1.78g懵逼
windbg 分析
1. 看看当前进程的 commit 内存有多大
0:000> !address -summary Mapping file section regions... Mapping module regions... Mapping PEB regions... Mapping TEB and stack regions... Mapping heap regions... Mapping page heap regions... Mapping other regions... Mapping stack trace database regions... Mapping activation context regions... --- Usage Summary ---------------- RgnCount ----------- Total Size -------- %ofBusy %ofTotal Free 402 7df9`8ed48000 ( 125.975 TB) 98.42% <unknown> 1239 206`619ca000 ( 2.025 TB) 99.99% 1.58% Image 1833 0`0b792000 ( 183.570 MB) 0.01% 0.00% Heap 36 0`02cdf000 ( 44.871 MB) 0.00% 0.00% Stack 111 0`01240000 ( 18.250 MB) 0.00% 0.00% Other 13 0`001e2000 ( 1.883 MB) 0.00% 0.00% TEB 37 0`0004a000 ( 296.000 kB) 0.00% 0.00% PEB 1 0`00001000 ( 4.000 kB) 0.00% 0.00% --- Type Summary (for busy) ------ RgnCount ----------- Total Size -------- %ofBusy %ofTotal MEM_MAPPED 326 200`00c57000 ( 2.000 TB) 98.76% 1.56% MEM_PRIVATE 1111 6`64ebf000 ( 25.577 GB) 1.23% 0.02% MEM_IMAGE 1833 0`0b792000 ( 183.570 MB) 0.01% 0.00% --- State Summary ---------------- RgnCount ----------- Total Size -------- %ofBusy %ofTotal MEM_FREE 402 7df9`8ed48000 ( 125.975 TB) 98.42% MEM_RESERVE 431 205`5900d000 ( 2.021 TB) 99.79% 1.58% MEM_COMMIT 2839 1`1829b000 ( 4.378 GB) 0.21% 0.00% --- Protect Summary (for commit) - RgnCount ----------- Total Size -------- %ofBusy %ofTotal PAGE_READWRITE 978 1`08d1c000 ( 4.138 GB) 0.20% 0.00% PAGE_EXECUTE_READ 308 0`07428000 ( 116.156 MB) 0.01% 0.00% PAGE_READONLY 1061 0`0487b000 ( 72.480 MB) 0.00% 0.00% PAGE_NOACCESS 139 0`02909000 ( 41.035 MB) 0.00% 0.00% PAGE_EXECUTE_READWRITE 41 0`00a6f000 ( 10.434 MB) 0.00% 0.00% PAGE_WRITECOPY 273 0`004cf000 ( 4.809 MB) 0.00% 0.00% PAGE_READWRITE|PAGE_GUARD 37 0`00071000 ( 452.000 kB) 0.00% 0.00% PAGE_EXECUTE_WRITECOPY 2 0`00024000 ( 144.000 kB) 0.00% 0.00% --- Largest Region by Usage ----------- Base Address -------- Region Size ---------- Free 18b`42fc0000 7c69`2df10000 ( 124.411 TB) <unknown> 7dfb`9b527000 1f9`b0c13000 ( 1.975 TB) Image 18a`10662000 0`00d7d000 ( 13.488 MB) Heap 18a`13631000 0`00f5e000 ( 15.367 MB) Stack 44`0acd0000 0`0007b000 ( 492.000 kB) Other 185`c4a60000 0`00181000 ( 1.504 MB) TEB 44`0ae08000 0`00002000 ( 8.000 kB) PEB 44`0afac000 0`00001000 ( 4.000 kB)
可以看出大概占了 4.378G,接下来再看看托管堆内存。
0:000> !eeheap -gc Number of GC Heaps: 4 ------------------------------ Heap 0 (00000185C55B4F90) generation 0 starts at 0x00000185C6C45838 generation 1 starts at 0x00000185C6C3DC88 generation 2 starts at 0x00000185C5CB1000 ephemeral segment allocation context: none segment begin allocated size 00000185C5CB0000 00000185C5CB1000 00000185C6EB1850 0x1200850(18876496) Large object heap starts at 0x00000189C5CB1000 segment begin allocated size 00000189C5CB0000 00000189C5CB1000 00000189D435D6F0 0xe6ac6f0(241878768) 0000018580000000 0000018580001000 00000185ADC5CD08 0x2dc5bd08(767933704) 0000018AE2FC0000 0000018AE2FC1000 0000018B3E878BC8 0x5b8b7bc8(1535867848) Heap Size: Size: 0x98dc0810 (2564556816) bytes. ------------------------------ Heap 1 (00000185C56835E0) generation 0 starts at 0x00000186C6C263D8 generation 1 starts at 0x00000186C6C18578 generation 2 starts at 0x00000186C5CB1000 ephemeral segment allocation context: none segment begin allocated size 00000186C5CB0000 00000186C5CB1000 00000186C7293328 0x15e2328(22946600) Large object heap starts at 0x00000189D5CB1000 segment begin allocated size 00000189D5CB0000 00000189D5CB1000 00000189D5F53350 0x2a2350(2761552) Heap Size: Size: 0x1884678 (25708152) bytes. ------------------------------ Heap 2 (00000185C5576960) generation 0 starts at 0x00000187C6C3B2A0 generation 1 starts at 0x00000187C6C334E0 generation 2 starts at 0x00000187C5CB1000 ephemeral segment allocation context: none segment begin allocated size 00000187C5CB0000 00000187C5CB1000 00000187C768E0D8 0x19dd0d8(27119832) Large object heap starts at 0x00000189E5CB1000 segment begin allocated size 00000189E5CB0000 00000189E5CB1000 00000189F326E728 0xd5bd728(224122664) Heap Size: Size: 0xef9a800 (251242496) bytes. ------------------------------ Heap 3 (00000185C557E9B0) generation 0 starts at 0x00000188C6F71D30 generation 1 starts at 0x00000188C6F4F758 generation 2 starts at 0x00000188C5CB1000 ephemeral segment allocation context: none segment begin allocated size 00000188C5CB0000 00000188C5CB1000 00000188C7543728 0x1892728(25765672) Large object heap starts at 0x00000189F5CB1000 segment begin allocated size 00000189F5CB0000 00000189F5CB1000 00000189F5D310C0 0x800c0(524480) 0000018AB2FC0000 0000018AB2FC1000 0000018AE0C1CD08 0x2dc5bd08(767933704) 0000018A14590000 0000018A14591000 0000018A2B3BEF20 0x16e2df20(383967008) Heap Size: Size: 0x4639c410 (1178190864) bytes. ------------------------------ GC Heap Size: Size: 0xef97ba98 (4019698328) bytes.
查看托管堆
0:000> !dumpheap -stat 0000018AE2FC1000 0000018B3E878BC8 Statistics: MT Count TotalSize Class Name 00000185c56d3570 1 30 Free 00007ffb0720ee48 1 1535867816 System.Collections.Generic.Dictionary`2+Entry[[System.Int32, System.Private.CoreLib],[System.Int32, System.Private.CoreLib]][] Total 2 objects
0:000> !dumpheap -mt 00007ffb0720ee48 0000018AE2FC1000 0000018B3E878BC8
Address MT Size
0000018ae2fc1020 00007ffb0720ee48 1535867816
Statistics:
MT Count TotalSize Class Name
00007ffb0720ee48 1 1535867816 System.Collections.Generic.Dictionary`2+Entry[[System.Int32, System.Private.CoreLib],[System.Int32, System.Private.CoreLib]][]
Total 1 objects
0:000> !DumpHeap /d -mt 00007ffb0720ee48
Address MT Size
00000185c6a56ac8 00007ffb0720ee48 616
0000018580001020 00007ffb0720ee48 767933672
0000018ae2fc1020 00007ffb0720ee48 1535867816
00000188c6da9e30 00007ffb0720ee48 296
0000018ab2fc1020 00007ffb0720ee48 767933672
Statistics:
MT Count TotalSize Class Name
00007ffb0720ee48 5 3071736072 System.Collections.Generic.Dictionary`2+Entry[[System.Int32, System.Private.CoreLib],[System.Int32, System.Private.CoreLib]][]
Total 5 objects
Fragmented blocks larger than 0.5 MB:
Addr Size Followed by
00000185C6AE9878 0.6MB 00000185C6B8CAA8 System.Byte[]
00000186C6E723F0 4.1MB 00000186C72912D8 System.Byte[]
00000187C715B2B8 5.2MB 00000187C768C088 System.Byte[]
00000188C6E2E7D8 0.6MB 00000188C6ED1A08 System.Byte[]
0:000> !gcroot 0000018ae2fc1020
Thread be58:
000000440BF3B6C0 00007FFAAAE74E00 Xw.Service.ProductCategoryService.GetParentCategoryId(Int32, System.Collections.Generic.Dictionary`2<Int32,Int32>, Int32 ByRef)
rdi:
-> 00000185C6A64458 System.Collections.Generic.Dictionary`2[[System.Int32, System.Private.CoreLib],[System.Int32, System.Private.CoreLib]]
-> 0000018AE2FC1020 System.Collections.Generic.Dictionary`2+Entry[[System.Int32, System.Private.CoreLib],[System.Int32, System.Private.CoreLib]][]
看到这行代价就大概知道是什么问题了，果断查询项目文件，才发现，这个方法是一个递归方法。因为数据的原因导致出现了无限递归，所以导致 System.Int32 和System.Collections.Generic.Dictionary 都很高
非常感谢博客园里面的大佬
https://www.cnblogs.com/huangxincheng/p/14830664.html
也是按照他的来一步步分析的。