Re: pg_rewind success even though getting error 'record with incorrect prev-link'

On 1/29/19 9:57 PM, Abdullah Al Maruf wrote:
> Hi Michael
>
> > This is pointing out to the end of WAL for the current timeline.  You
> > may face it after reading a WAL segment in an area which has been used
> > in the past for a recycled segment.
>
> Are you talking about error `LOG:  invalid record length at 0/B000098:
> wanted 24, got 0` ?
> or,
>  `LOG:  record with incorrect prev-link 10000/21B0000 at 0/B000098`
>
> Actually, the 1st error is not making any issue. This node starts to
> streaming from primary successfully.
> But when the second error comes, It appears every 5 seconds. And, the node
> is not streaming from master.
>
> pg_rewind still resolves timeline conflict, but it's not fixing this
> second error.
>
> Any work around??
> ----------------
> My scenario, in short, I have 1 master nodes (0th node) and three standby
> nodes (1st,
>
> 2nd & 3rd node). When I make the 3rd node as master (by trigger file) and
> restarts 0th node as a replica, It shows no problem.
>
> But when both nodes are offline and our leader selection chooses the 0th
> node as a master, and tries to reattach the 3rd node as Replica, It throws
> an error similar to:
>
> ``` LOG: invalid record length at 0/B000098: wanted 24, got 0 LOG: started
> streaming WAL from primary at 0/B000000 on timeline 2 LOG: record with
> incorrect prev-link 10000/21B0000 at 0/B000098 FATAL: terminating
> walreceiver process due to administrator command LOG: record with
> incorrect prev-link 10000/21B0000 at 0/B000098 LOG: record with incorrect
> prev-link 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098 LOG: record with incorrect prev-link
> 10000/21B0000 at 0/B000098
>

The only *error* I see is when you apparently manually kill the process. 
The LOG messages aren't actually errors.

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