'indexer' exited (*timekeeper).sendRestartMsg

This looks same as MB-15323 (but repro in watson)

During tpcc 6 nodes, 10 buckets.

Service 'indexer' exited with status 1. Restarting. Messages: runtime.goexit()
/home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/asm_amd64.s:1998 +0x1 fp=0xc826184798 sp=0xc826184790
created by github.com/couchbase/indexing/secondary/indexer.(*timekeeper).startTimer
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/indexing/secondary/indexer/timekeeper.go:2714 +0x29a
[goport] 2016/03/23 11:42:13 /opt/couchbase/bin/indexer terminated: signal: aborted (core dumped)

(gdb) t 1
[Switching to thread 1 (LWP 9105)]
#0 runtime.raise () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/sys_linux_amd64.s:110
110 in /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/sys_linux_amd64.s
(gdb) bt
#0 runtime.raise () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/sys_linux_amd64.s:110
#1 0x0000000000444148 in runtime.dieFromSignal (sig=6) at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/signal1_unix.go:192
#2 0x000000000044426f in runtime.crash () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/signal1_unix.go:247
#3 0x0000000000431cce in runtime.dopanic_m (gp=0xc82933d200, pc=4395526, sp=859530664248)
at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/panic.go:642
#4 0x0000000000458312 in runtime.dopanic.func1 () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/panic.go:517
#5 0x0000000000461739 in runtime.systemstack () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/asm_amd64.s:291
#6 0x0000000000435b20 in runtime.startTheWorldWithSema () at /home/couchbase/.cbdepscache/exploded/x86_64/go-1.6/go/src/runtime/proc.go:983
#7 0x000000c820022a00 in ?? ()
#8 0x0000000000000000 in ?? ()