Issue with a hanging apply process on the replica db after vacuum works on primary

Hi all!

May someone help me with the issue in the apply process on the replica.
We have a stream replication and after vacuum stops working with a big
table we get a "freeze" in applying data on the replica database. It
looks like this:

Tue Feb 24 15:04:51 MSK 2015 Stream: MASTER-masterdb:79607136410456
SLAVE:79607136410456 Replay:79607136339456 :: REPLAY 69 KBytes
(00:00:00.294485 seconds)
Tue Feb 24 15:04:52 MSK 2015 Stream: MASTER-masterdb:79607137892672
SLAVE:79607137715392 Replay:79607137715392 :: REPLAY 173 KBytes
(00:00:00.142605 seconds)
Tue Feb 24 15:04:53 MSK 2015 Stream: MASTER-masterdb:79607139327776
SLAVE:79607139241816 Replay:79607139241816 :: REPLAY 84 KBytes
(00:00:00.05223 seconds)
Tue Feb 24 15:04:54 MSK 2015 Stream: MASTER-masterdb:79607141134776
SLAVE:79607141073344 Replay:79607141080032 :: REPLAY 54 KBytes
(00:00:00.010603 seconds)
Tue Feb 24 15:04:55 MSK 2015 Stream: MASTER-masterdb:79607143085176
SLAVE:79607143026440 Replay:79607143038040 :: REPLAY 46 KBytes
(00:00:00.009506 seconds)
Tue Feb 24 15:04:56 MSK 2015 Stream: MASTER-masterdb:79607145111280
SLAVE:79607145021384 Replay:79607145025664 :: REPLAY 83 KBytes
(00:00:00.006795 seconds)
Tue Feb 24 15:04:57 MSK 2015 Stream: MASTER-masterdb:79607146564424
SLAVE:79607146478336 Replay:79607146501264 :: REPLAY 61 KBytes
(00:00:00.00701 seconds)
Tue Feb 24 15:04:58 MSK 2015 Stream: MASTER-masterdb:79607148160680
SLAVE:79607148108352 Replay:79607147369320 :: REPLAY 773 KBytes
(00:00:00.449702 seconds)
Tue Feb 24 15:04:59 MSK 2015 Stream: MASTER-masterdb:79607150220688
SLAVE:79607150159632 Replay:79607150171312 :: REPLAY 48 KBytes
(00:00:00.006594 seconds)
Tue Feb 24 15:05:00 MSK 2015 Stream: MASTER-masterdb:79607152365360
SLAVE:79607152262696 Replay:79607152285240 :: REPLAY 78 KBytes
(00:00:00.007042 seconds)
Tue Feb 24 15:05:02 MSK 2015 Stream: MASTER-masterdb:79607154049848
SLAVE:79607154012624 Replay:79607153446800 :: REPLAY 589 KBytes
(00:00:00.513637 seconds)
Tue Feb 24 15:05:03 MSK 2015 Stream: MASTER-masterdb:79607155229992
SLAVE:79607155187864 Replay:79607155188312 :: REPLAY 41 KBytes
(00:00:00.004773 seconds)
Tue Feb 24 15:05:04 MSK 2015 Stream: MASTER-masterdb:79607156833968
SLAVE:79607156764128 Replay:79607156785488 :: REPLAY 47 KBytes
(00:00:00.006846 seconds)
Tue Feb 24 15:05:05 MSK 2015 Stream: MASTER-masterdb:79607158419848
SLAVE:79607158344856 Replay:79607158396352 :: REPLAY 23 KBytes
(00:00:00.005228 seconds)
Tue Feb 24 15:05:06 MSK 2015 Stream: MASTER-masterdb:79607160004776
SLAVE:79607159962400 Replay:79607159988888 :: REPLAY 16 KBytes
(00:00:00.003162 seconds)
*--here apply process just stops*

Tue Feb 24 15:05:07 MSK 2015 Stream: MASTER-masterdb:79607161592048
SLAVE:79607161550576 Replay:79607160986064 :: REPLAY 592 KBytes
(00:00:00.398376 seconds)
Tue Feb 24 15:05:08 MSK 2015 Stream: MASTER-masterdb:79607163272840
SLAVE:79607163231384 Replay:79607160986064 :: REPLAY 2233 KBytes
(00:00:01.446759 seconds)
Tue Feb 24 15:05:09 MSK 2015 Stream: MASTER-masterdb:79607164958632
SLAVE:79607164904448 Replay:79607160986064 :: REPLAY 3879 KBytes
(00:00:02.497181 seconds)
Tue Feb 24 15:05:10 MSK 2015 Stream: MASTER-masterdb:79607166819560
SLAVE:79607166777712 Replay:79607160986064 :: REPLAY 5697 KBytes
(00:00:03.543107 seconds)
Tue Feb 24 15:05:11 MSK 2015 Stream: MASTER-masterdb:79607168595280
SLAVE:79607168566536 Replay:79607160986064 :: REPLAY 7431 KBytes
(00:00:04.589736 seconds)
Tue Feb 24 15:05:12 MSK 2015 Stream: MASTER-masterdb:79607170372064
SLAVE:79607170252480 Replay:79607160986064 :: REPLAY 9166 KBytes
(00:00:05.635918 seconds)
Tue Feb 24 15:05:13 MSK 2015 Stream: MASTER-masterdb:79607171829480
SLAVE:79607171714144 Replay:79607160986064 :: REPLAY 10589 KBytes
(00:00:06.688115 seconds)
Tue Feb 24 15:05:14 MSK 2015 Stream: MASTER-masterdb:79607173152488
SLAVE:79607173152488 Replay:79607160986064 :: REPLAY 11881 KBytes
(00:00:07.736993 seconds)
Tue Feb 24 15:05:15 MSK 2015 Stream: MASTER-masterdb:79607174149968
SLAVE:79607174149968 Replay:79607160986064 :: REPLAY 12855 KBytes
(00:00:08.78538 seconds)
Tue Feb 24 15:05:16 MSK 2015 Stream: MASTER-masterdb:79607176448344
SLAVE:79607176252088 Replay:79607160986064 :: REPLAY 15100 KBytes
(00:00:09.835184 seconds)
Tue Feb 24 15:05:17 MSK 2015 Stream: MASTER-masterdb:79607177632216
SLAVE:79607177608224 Replay:79607160986064 :: REPLAY 16256 KBytes
(00:00:10.926493 seconds)
Tue Feb 24 15:05:18 MSK 2015 Stream: MASTER-masterdb:79607179432960
SLAVE:79607179378096 Replay:79607160986064 :: REPLAY 18015 KBytes
(00:00:11.97989 seconds)
Tue Feb 24 15:05:19 MSK 2015 Stream: MASTER-masterdb:79607180893384
SLAVE:79607180874256 Replay:79607160986064 :: REPLAY 19441 KBytes
(00:00:13.028921 seconds)
Tue Feb 24 15:05:20 MSK 2015 Stream: MASTER-masterdb:79607182596224
SLAVE:79607182552272 Replay:79607160986064 :: REPLAY 21104 KBytes
(00:00:14.079497 seconds)
Tue Feb 24 15:05:21 MSK 2015 Stream: MASTER-masterdb:79607183935312
SLAVE:79607183902592 Replay:79607160986064 :: REPLAY 22411 KBytes
(00:00:15.127679 seconds)
Tue Feb 24 15:05:23 MSK 2015 Stream: MASTER-masterdb:79607185165880
SLAVE:79607185094032 Replay:79607160986064 :: REPLAY 23613 KBytes
(00:00:16.175132 seconds)
Tue Feb 24 15:05:24 MSK 2015 Stream: MASTER-masterdb:79607187196920
SLAVE:79607187169368 Replay:79607160986064 :: REPLAY 25596 KBytes
(00:00:17.221981 seconds)
Tue Feb 24 15:05:25 MSK 2015 Stream: MASTER-masterdb:79607188943856
SLAVE:79607188885952 Replay:79607160986064 :: REPLAY 27302 KBytes
(00:00:18.274362 seconds)
Tue Feb 24 15:05:26 MSK 2015 Stream: MASTER-masterdb:79607190489400
SLAVE:79607190443160 Replay:79607160986064 :: REPLAY 28812 KBytes
(00:00:19.319987 seconds)
Tue Feb 24 15:05:27 MSK 2015 Stream: MASTER-masterdb:79607192089312
SLAVE:79607192054048 Replay:79607160986064 :: REPLAY 30374 KBytes
(00:00:20.372305 seconds)
Tue Feb 24 15:05:28 MSK 2015 Stream: MASTER-masterdb:79607193736800
SLAVE:79607193690056 Replay:79607160986064 :: REPLAY 31983 KBytes
(00:00:21.421359 seconds)
Tue Feb 24 15:05:29 MSK 2015 Stream: MASTER-masterdb:79607195968648
SLAVE:79607195901296 Replay:79607160986064 :: REPLAY 34163 KBytes
(00:00:22.471334 seconds)
Tue Feb 24 15:05:30 MSK 2015 Stream: MASTER-masterdb:79607197808840
SLAVE:79607197737720 Replay:79607160986064 :: REPLAY 35960 KBytes
(00:00:23.52269 seconds)
Tue Feb 24 15:05:31 MSK 2015 Stream: MASTER-masterdb:79607199571144
SLAVE:79607199495976 Replay:79607160986064 :: REPLAY 37681 KBytes
(00:00:24.577615 seconds)
Tue Feb 24 15:05:32 MSK 2015 Stream: MASTER-masterdb:79607201206104
SLAVE:79607201100392 Replay:79607160986064 :: REPLAY 39277 KBytes
(00:00:25.624604 seconds)
Tue Feb 24 15:05:33 MSK 2015 Stream: MASTER-masterdb:79607203174208
SLAVE:79607203111136 Replay:79607160986064 :: REPLAY 41199 KBytes
(00:00:26.67059 seconds)
Tue Feb 24 15:05:34 MSK 2015 Stream: MASTER-masterdb:79607204792888
SLAVE:79607204741600 Replay:79607160986064 :: REPLAY 42780 KBytes
(00:00:27.719088 seconds)
Tue Feb 24 15:05:35 MSK 2015 Stream: MASTER-masterdb:79607206453216
SLAVE:79607206409032 Replay:79607160986064 :: REPLAY 44401 KBytes
(00:00:28.766647 seconds)
Tue Feb 24 15:05:36 MSK 2015 Stream: MASTER-masterdb:79607208225344
SLAVE:79607208142176 Replay:79607160986064 :: REPLAY 46132 KBytes
(00:00:29.811434 seconds)

perf shows the following functions on the top
+ 22.50% postmaster [kernel.kallsyms] [k] copy_user_generic_string
+ 8.48% postmaster postgres [.] hash_search_with_hash_value

after 10 minutes or so the apply process continue to work

Tue Feb 24 15:13:25 MSK 2015 Stream: MASTER-masterdb:79608758742560
SLAVE:79608758718008 Replay:79607160986064 :: REPLAY 1560309 KBytes
(00:08:19.009653 seconds)
Tue Feb 24 15:13:26 MSK 2015 Stream: MASTER-masterdb:79608759203608
SLAVE:79608759189680 Replay:79607160986064 :: REPLAY 1560759 KBytes
(00:08:20.057877 seconds)
Tue Feb 24 15:13:27 MSK 2015 Stream: MASTER-masterdb:79608759639680
SLAVE:79608759633224 Replay:79607160986064 :: REPLAY 1561185 KBytes
(00:08:21.104723 seconds)
Tue Feb 24 15:13:28 MSK 2015 Stream: MASTER-masterdb:79608760271200
SLAVE:79608760264128 Replay:79607160986064 :: REPLAY 1561802 KBytes
(00:08:22.148546 seconds)
Tue Feb 24 15:13:30 MSK 2015 Stream: MASTER-masterdb:79608760622920
SLAVE:79608760616656 Replay:79607160986064 :: REPLAY 1562145 KBytes
(00:08:23.196645 seconds)
Tue Feb 24 15:13:31 MSK 2015 Stream: MASTER-masterdb:79608761122040
SLAVE:79608761084584 Replay:79607160986064 :: REPLAY 1562633 KBytes
(00:08:24.240653 seconds)
Tue Feb 24 15:13:32 MSK 2015 Stream: MASTER-masterdb:79608761434200
SLAVE:79608761426080 Replay:79607160986064 :: REPLAY 1562938 KBytes
(00:08:25.289429 seconds)
Tue Feb 24 15:13:33 MSK 2015 Stream: MASTER-masterdb:79608761931008
SLAVE:79608761904808 Replay:79607160986064 :: REPLAY 1563423 KBytes
(00:08:26.338498 seconds)
*--apply starts*
Tue Feb 24 15:13:34 MSK 2015 Stream: MASTER-masterdb:79608762360568
SLAVE:79608762325712 Replay:79607163554680 :: REPLAY 1561334 KBytes
(00:08:25.702423 seconds)
Tue Feb 24 15:13:35 MSK 2015 Stream: MASTER-masterdb:79608762891224
SLAVE:79608762885928 Replay:79607166466488 :: REPLAY 1559008 KBytes
(00:08:25.011046 seconds)
Tue Feb 24 15:13:36 MSK 2015 Stream: MASTER-masterdb:79608763681920
SLAVE:79608763667256 Replay:79607167054056 :: REPLAY 1559207 KBytes
(00:08:25.827531 seconds)
Tue Feb 24 15:13:37 MSK 2015 Stream: MASTER-masterdb:79608764207088
SLAVE:79608764197744 Replay:79607175610296 :: REPLAY 1551364 KBytes
(00:08:21.182428 seconds)
Tue Feb 24 15:13:38 MSK 2015 Stream: MASTER-masterdb:79608764857920
SLAVE:79608764832432 Replay:79607183599632 :: REPLAY 1544197 KBytes
(00:08:16.742467 seconds)
Tue Feb 24 15:13:39 MSK 2015 Stream: MASTER-masterdb:79608765323360
SLAVE:79608765281408 Replay:79607186862176 :: REPLAY 1541466 KBytes
(00:08:15.569874 seconds)
Tue Feb 24 15:13:40 MSK 2015 Stream: MASTER-masterdb:79608765848240
SLAVE:79608765824520 Replay:79607186862176 :: REPLAY 1541978 KBytes
(00:08:16.620932 seconds)

All this is a result of completion of "vacuum verbose analyze
master_table" on the master site

Any help would be appreciated

--
Best regards,
Sergey Shchukin