I just realized that if the clock on region server(s) drifts over
relatively long period of time (assuming region server stays up), the
following mechanism wouldn't work.
FYI
On Fri, Mar 15, 2013 at 5:07 PM, Ted Yu <yuzhih...@gmail.com> wrote:
> When a region server reports to master the first time, ServerManager does
> the following check:
>
> * Checks if the clock skew between the server and the master. If the
> clock skew exceeds the
>
> * configured max, it will throw an exception; if it exceeds the
> configured warning threshold,
>
> * it will log a warning but start normally.
> The unit is in milliseconds.
> These two parameters are configurable.
>
> Please take a look at the source code if possible - the code should come
> with tar ball.
>
> Cheers
>
> On Fri, Mar 15, 2013 at 4:50 PM, <yulin...@dell.com> wrote:
>
>> Hi Ted,
>>
>> For the source code below, what's the unit of 30000? Is the maxSkew 30
>> seconds? Also, what does Hbase do when the time skew exeeds 10 seconds and
>> 30 seconds? Are these two values configurable?
>>
>> Thanks,
>>
>> YuLing
>> >maxSkew = c.getLong("hbase.master.maxclockskew", 30000);
>> > warningSkew = c.getLong("hbase.master.warningclockskew", 10000);
>> > ./src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
>>
>>
>> -----Original Message-----
>> From: Ted Yu [mailto:yuzhih...@gmail.com]
>> Sent: Friday, March 15, 2013 4:28 PM
>> To: user@hbase.apache.org
>> Subject: Re: hbase time skew
>>
>> Please upgrade to 0.94.5, if possible.
>>
>> There have been a lot of bug fixes and performance improvements since
>> 0.94.1.
>>
>> On Fri, Mar 15, 2013 at 4:26 PM, <yulin...@dell.com> wrote:
>>
>> > Yes, I'm using 0.94.1.
>> >
>> > -----Original Message-----
>> > From: Ted Yu [mailto:yuzhih...@gmail.com]
>> > Sent: Friday, March 15, 2013 3:53 PM
>> > To: user@hbase.apache.org
>> > Subject: Re: hbase time skew
>> >
>> > Are you using 0.94.x ?
>> >
>> > If so, see the following:
>> >
>> > maxSkew = c.getLong("hbase.master.maxclockskew", 30000);
>> > warningSkew = c.getLong("hbase.master.warningclockskew", 10000);
>> > ./src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
>> >
>> > Cheers
>> >
>> > On Fri, Mar 15, 2013 at 3:49 PM, <yulin...@dell.com> wrote:
>> >
>> > > Hi,
>> > >
>> > > We recently encountered the issue that HBase tables got into a state
>> > > that was not disabled nor enabled. We found that the root cause was
>> > > the linux clock skewed more than 5 hours. I googled and understood
>> > > that hbase can only handle about a couple of seconds time skew. We
>> > > were wondering if there's any configuration in HBase that we can do
>> > > so as to increase the number of seconds that hbase could handle?
>> > >
>> > > Thanks very much,
>> > >
>> > > YuLing
>> > >
>> >
>>
>
>
