Am 29.03.2010 23:35, schrieb Ted Yu:
> https://issues.apache.org/jira/browse/HBASE-2391 has been filed.
>
> We call HBaseAdmin.isMasterRunning() to see if client has connection with
> HBase. If there is a working alternative, we'd love to use it.
>
Just to catch up on this....what is the recommended way to
programmatically check if Hbase is up (say on 0.20.4)?
Thx,
Al
> ...
> On Mon, Mar 29, 2010 at 2:25 PM, Jean-Daniel Cryans
> <jdcry...@apache.org>wrote:
>
>> I think this method wasn't updated when we moved to Zookeeper (since
>> in pre-0.20, dead master = dead cluster), also looking at when this is
>> called, I only see it from HMerge and HBaseAdmin.isMasterRunning()...
>> which in turn isn't called anywhere in the java code (I think we call
>> it in the shell tho).
>>
>> So we should first consider if this method is useful at all, and if so
>> then what would be the best fix. For example, if you run a HMerge
>> while the master is down but the region servers are up, you're going
>> to end up with something wrong since it expects hbase to be completely
>> down.
>>
>> Can you open a jira to continue discussions there?
>>
>> Thx!
>>
>> J-D
>>
>> On Mon, Mar 29, 2010 at 2:01 PM, Ted Yu <yuzhih...@gmail.com> wrote:
>>> Hi,
>>> While going over TableServers.isMasterRunning() in HConnectionManager, I
>> see
>>> this:
>>> public boolean isMasterRunning() {
>>> if (this.master == null) {
>>> try {
>>> getMaster();
>>>
>>> } catch (MasterNotRunningException e) {
>>> return false;
>>> }
>>> }
>>> return true;
>>> }
>>> When isMasterRunning() is called the first time, if master is obtained
>>> successfully, master field would contain reference to HMasterInterface.
>>> Subsequent calls to isMasterRunning() wouldn't throw
>>> MasterNotRunningException even if master server stops responding to
>> clients.
>>>
>>> I think master.isMasterRunning() should be called if master isn't null.
>>>
>>> Regards
>>>
>>
>
