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From Adar Lieber-Dembo <a...@cloudera.com>
Subject Re: kudu-tserver can not be started
Date Wed, 31 Oct 2018 00:31:10 GMT
It is possible for a tserver's memory consumption to exceed
--memory_limit_hard_bytes if the tserver is hosting an excessive
amount of tablets (or tablet data blocks). That's usually a sign that
the tserver is overloaded relative to the amount of resources
allocated to it by the operator, and should either shed load (i.e.
tablets), or should be given more memory. Put another way, there's
overhead associated with each hosted tablet that must be accounted for
in the memory limit; this overhead is usually small unless the tserver
is in excess of Kudu's scale limits
(https://kudu.apache.org/docs/known_issues.html#_scale).

In any case, I don't see how this can lead to a machine crash. The
Linux out-of-memory (oom) killer will kill a memory intensive process
when the system is under too much memory pressure, and Kudu is no
exception.

Could you provide more information on this specific case? What is the
configured value of --memory_limit_hard_bytes? How many tablets is the
failing tserver hosting? How much data is on the node? Sharing the
tserver log (beginning with its startup) would help here.


On Tue, Oct 30, 2018 at 8:15 AM zoujie@archly.cc <zoujie@archly.cc> wrote:
>
> Hi:
>       I used  Kudu version 1.4.0(1 master  , 3 tserver), and there is a problem :
tserver can't be started, the process will run out of operating system memory, resulting in
the use of swap partitions, resulting in high CPU load and machine crash. The --memory_limit_hard_bytes
flag does not take effect.
>
>
> ________________________________
> zoujie@archly.cc

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