When the active name node crashes, it seems there is always a chance that
the data blocks in flight will be missing.
My understanding is that when the active name node crashes, the metadata of
data blocks in transition which exist in active name node memory is not
successfully captured by journal
Hi Chen!
>From my understanding, every operation on the Namenode is logged (and flushed)
>to disk / QJM / shared storage. This includes the addBlock operation. So when
>a client requests to write a new block, the metadata is logged by the active
>NN, so even if it crashes later on, the new activ
Thanks for the reply, Ravi.
In my case, what I see constantly is there are always missing blocks every
time active name node crashes. The active name node crashes because of
timeout on journal nodes.
Could this be a specific case which could lead to missing blocks?
Chen
On Tue, Feb 10, 2015 at
-05:00)
To: user@hadoop.apache.org, Ravi Prakash
Cc: Subject: Re: missing data blocks after active name
node crashes
Thanks for the reply, Ravi.
In my case, what I see constantly is there are always missing blocks every
time active name node crashes. The active name node crashes because of
t process. The missing blocks will get reported eventually.
>
>
> Original message
> From: Chen Song
> Date:02/10/2015 2:44 PM (GMT-05:00)
> To: user@hadoop.apache.org, Ravi Prakash
> Cc:
> Subject: Re: missing data blocks after active name node crashe
https://issues.apache.org/jira/browse/HDFS-7097
Original message From: Chen Song
Date:02/11/2015 7:48 AM (GMT-05:00)
To: user@hadoop.apache.org Cc: Subject: Re:
missing data blocks after active name node crashes
Thanks David.
Do you have the relative Jira ticket
tandby NN
>> would not process block reports from the DNs when it was dealing with the
>> checkpoint process. The missing blocks will get reported eventually.
>>
>>
>> Original message
>> From: Chen Song
>> Date:02/10/2015 2:44 PM (GMT-05:00)
