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HBase, mail # user - GC pause issues


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答复: GC pause issues
谢良 2013-01-25, 02:07
Hi Varun,

Please note if you try to increase new generation size, then the "ParNew" time will be up accordingly, and CMS YGC is also a STW.
could you have a try to reduce memstore size to a smaller value, e.g. 128m or 256m ?

Regards,
Liang
________________________________________
发件人: Varun Sharma [[EMAIL PROTECTED]]
发送时间: 2013年1月25日 1:40
收件人: [EMAIL PROTECTED]
主题: GC pause issues

Hi,

I have a region server which has the following logs. As you can see from
the log, ParNew is sufficiently big (450M) and there are heavy writes going
in. I am seeing 200ms pauses which eventually build up and there is a
promotion failure. There is a parnew collection every 2-3 seconds so it
fills up real fast. My memstore size is bigger 512m for flushes and 4
regions per server. (overall size is 3G for all memstores) - I have mslab
enabled

2013-01-24T13:08:16.870+0000: 63533.964: [GC 63533.964: [ParNew:
471841K->52416K(471872K), 0.2251880 secs] 8733008K->8445039K(12727104K),
0.2254100 secs] [Times: user=0.50 sys=0.18, real=0.22 secs]
2013-01-24T13:08:19.546+0000: 63536.639: [GC 63536.639: [ParNew:
461593K->52416K(471872K), 0.2812690 secs] 8854216K->8557572K(12727104K),
0.2814870 secs] [Times: user=0.66 sys=0.09, real=0.29 secs]
013-01-24T13:08:21.824+0000: 63538.917: [GC 63538.918: [ParNew:
442836K->52416K(471872K), 0.2781490 secs] 8947992K->8705355K(12727104K),
0.2783810 secs] [Times: user=0.58 sys=0.14, real=0.28 secs]
2013-01-24T13:08:22.122+0000: 63539.216: [GC [1 CMS-initial-mark:
8652939K(12255232K)] 8752914K(12727104K), 0.0365000 secs] [Times: user=0.02
sys=0.00, real=0.04 secs]
2013-01-24T13:08:22.159+0000: 63539.253: [CMS-concurrent-mark-start]
2013-01-24T13:08:24.953+0000: 63542.047: [GC 63542.047: [ParNew:
471872K->52251K(471872K), 0.1611970 secs] 9124811K->8831437K(12727104K),
0.1614180 secs] [Times: user=0.37 sys=0.19, real=0.16 secs]
2013-01-24T13:08:26.434+0000: 63543.527: [CMS-concurrent-mark: 4.105/4.268
secs] [Times: user=5.36 sys=0.34, real=4.27 secs]
2013-01-24T13:08:26.434+0000: 63543.527: [CMS-concurrent-preclean-start]
2013-01-24T13:08:26.597+0000: 63543.691: [CMS-concurrent-preclean:
0.133/0.163 secs] [Times: user=0.16 sys=0.05, real=0.17 secs]
2013-01-24T13:08:26.597+0000: 63543.691:
[CMS-concurrent-abortable-preclean-start]
2013-01-24T13:08:27.401+0000: 63544.495:
[CMS-concurrent-abortable-preclean: 0.792/0.804 secs] [Times: user=1.46
sys=0.16, real=0.80 secs]
2013-01-24T13:08:27.403+0000: 63544.496: [GC[YG occupancy: 274458 K (471872
K)]63544.496: [Rescan (parallel) , 0.0540730 secs]63544.551: [weak refs
processing, 0.0001700 secs] [1 CMS-remark: 8779186K(12255232K)]
9053645K(12727104K), 0.0544410 secs] [Times: user=0.20 sys=0.01, real=0.06
secs]
2013-01-24T13:08:27.458+0000: 63544.551: [CMS-concurrent-sweep-start]
2013-01-24T13:08:27.955+0000: 63545.048: [GC 63545.049: [ParNew:
471707K->44566K(471872K), 0.1371770 secs] 9044714K->8701862K(12727104K),
0.1374060 secs] [Times: user=0.35 sys=0.12, real=0.14 secs]
2013-01-24T13:08:29.285+0000: 63546.378: [GC 63546.478: [ParNew:
445714K->52416K(471872K), 0.5626120 secs] 8648805K->8410223K(12727104K),
0.5628610 secs] [Times: user=0.91 sys=0.08, real=0.66 secs]
2013-01-24T13:08:32.308+0000: 63549.401: [GC 63549.402: [ParNew:
471872K->52416K(471872K), 0.2300560 secs] 8247804K->7976043K(12727104K),
0.2302900 secs] [Times: user=0.62 sys=0.17, real=0.23 secs]
2013-01-24T13:08:34.844+0000: 63551.938: [GC 63551.938: [ParNew (promotion
failed): 471872K->471872K(471872K), 0.2788500 secs]63552.217:
[CMS2013-01-24T13:08:37.256+0000: 63554.349: [CMS-concurrent-sweep:
8.473/9.798 secs] [*Times: user=15.26 sys=1.11, real=9.80 secs*]

What might be advised here - should I up the size to 1G for the new
generation ?

Thanks
Varun