We have an application we have created using C#, RestSharp, Log4net and Quartz. The Quartz is running tasks every X amount of minutes (about five total tasks) that perform various functions but most of which is working with Active Directory and using RestSharp to communicate with an external service. What we have found is the memory of this service keeps growing until the service is restarted.
We are having a difficult time discovering where the memory leak is. We have gone through the entire code making sure everything was disposed of that has a dispose method, we have nulled StringBuilder objects and arrays we create within the Quartz tasks even though it shouldn't be necessary.
We have taken on the task of creating a process dump when the application is over 500MB (the process starts at 10MB). Examining with Windbg (which isn't my strong suite) we see this:
************************************************************************************************************************
NT HEAP STATS BELOW
************************************************************************************************************************
LFH Key : 0x75c77a1078572532
Termination on corruption : ENABLED
Heap Flags Reserv Commit Virt Free List UCR Virt Lock Fast
(k) (k) (k) (k) length blocks cont. heap
-------------------------------------------------------------------------------------
00000265d7670000 00000002 32604 21192 32552 720 298 6 1 3 LFH
00000265d74a0000 00008000 64 4 64 2 1 1 0 0
00000265d7640000 00001002 112 64 60 6 5 1 0 0 LFH
00000265d7960000 00001002 1132 88 1080 19 6 2 0 0 LFH
00000265d7ca0000 00001002 60 16 60 4 2 1 0 0
00000265d7dd0000 00041002 60 8 60 5 1 1 0 0
00000265f0680000 00041002 60 8 60 4 2 1 0 0
00000265f0d40000 00001002 533472 518492 533420 2810 712 37 0 0 LFH
-------------------------------------------------------------------------------------
Now from what we can tell is heap 00000265f0d40000 is taking all the memory. When I view this in dotMemory it shows only around 2-3MB of memory being used. My theory this is not .NET memory that is taking this up. We are not using PINVOKE or anything like that but maybe it could be the third party libraries we are using?
I am not really sure where to go from here since I find a lot of topics on looking at .NET memory and not native memory leaks:
0:026> !address 265f0d40000
Usage: Heap
Base Address: 00000265`f0d40000
End Address: 00000265`f0d4f000
Region Size: 00000000`0000f000 ( 60.000 kB)
State: 00001000 MEM_COMMIT
Protect: 00000004 PAGE_READWRITE
Type: 00020000 MEM_PRIVATE
Allocation Base: 00000265`f0d40000
Allocation Protect: 00000004 PAGE_READWRITE
More info: heap owning the address: !heap 0x265f0d40000
More info: heap segment
More info: heap entry containing the address: !heap -x 0x265f0d40000
0:026> !heap -x 0x265f0d40000
Entry User Heap Segment Size PrevSize Unused Flags
-------------------------------------------------------------------------------------------------------------
00000265f0d40000 00000265f0d40010 00000265f0d40000 00000265f0d40000 720 0 1 busy
0:026> !heap -stat -h 265f0d40000
heap @ 00000265f0d40000
group-by: TOTSIZE max-display: 20
size #blocks total ( %) (percent of total busy bytes)
370 3cece - d16e420 (44.25)
33b 6eb0 - 1659290 (4.72)
50 3cee6 - 130a7e0 (4.02)
359 452e - e796fe (3.06)
fd7 dd6 - db28ba (2.89)
318 4530 - d60c80 (2.83)
336 3758 - b1b490 (2.35)
42f 2982 - ada6de (2.29)
451 1bd3 - 7819c3 (1.59)
411 1bc3 - 70e3f3 (1.49)
3de 1bac - 6b0328 (1.41)
354 1bac - 5c1870 (1.22)
331 1bac - 584fec (1.17)
566 dd6 - 4ab144 (0.99)
4bd dd6 - 418efe (0.87)
491 dde - 3f52be (0.84)
484 dd6 - 3e7a58 (0.82)
47a dd6 - 3deffc (0.82)
477 dd6 - 3dc67a (0.82)
46a dd6 - 3d129c (0.81)
After running !heap -flt s 370 it will just print a ton of these:
0000026592e10470 0038 0038 [00] 0000026592e10480 00370 - (busy)
unknown!printable
0000026592e107f0 0038 0038 [00] 0000026592e10800 00370 - (busy)
unknown!printable
0000026592e10b70 0038 0038 [00] 0000026592e10b80 00370 - (busy)
unknown!printable
0000026592e10ef0 0038 0038 [00] 0000026592e10f00 00370 - (busy)
unknown!printable
0000026592e11270 0038 0038 [00] 0000026592e11280 00370 - (busy)
unknown!printable
0000026592e115f0 0038 0038 [00] 0000026592e11600 00370 - (busy)
unknown!printable
0000026592e11970 0038 0038 [00] 0000026592e11980 00370 - (busy)
unknown!printable
0000026592e11cf0 0038 0038 [00] 0000026592e11d00 00370 - (busy)
unknown!printable
0000026592e12070 0038 0038 [00] 0000026592e12080 00370 - (free)
0000026592e123f0 0038 0038 [00] 0000026592e12400 00370 - (busy)
unknown!printable
0000026592e12770 0038 0038 [00] 0000026592e12780 00370 - (free)
0000026592e12af0 0038 0038 [00] 0000026592e12b00 00370 - (free)
I would appreciate any assistance because I am at a loss. The memory will continue to grow to well over 1-2GB if we let it.
