Re: [HACKERS] WIP aPatch: Pgbench Serialization and deadlock errors

On Sun, 27 Mar 2022 15:28:41 +0900 (JST)
Tatsuo Ishii  wrote:

> > This patch has caused the PDF documentation to fail to build cleanly:
> > 
> > [WARN] FOUserAgent - The contents of fo:block line 1 exceed the available area in the inline-progression direction by more than 50 points. (See position 125066:375)
> > 
> > It's complaining about this:
> > 
> > 
> > interval_start num_transactions sum_latency sum_latency_2 min_latency max_latency { failures | serialization_failures deadlock_failures }  sum_lag sum_lag_2 min_lag max_lag  skipped    retried retries 
> > 
> > 
> > which runs much too wide in HTML format too, even though that toolchain
> > doesn't tell you so.
> 
> Yeah.
> 
> > We could silence the warning by inserting an arbitrary line break or two,
> > or refactoring the syntax description into multiple parts.  Either way
> > seems to create a risk of confusion.
> 
> I think we can fold the line nicely. Here is the rendered image.
> 
> Before:
> interval_start num_transactions sum_latency sum_latency_2 min_latency max_latency { failures | serialization_failures deadlock_failures } [ sum_lag sum_lag_2 min_lag max_lag [ skipped ] ] [ retried retries ]
> 
> After:
> interval_start num_transactions sum_latency sum_latency_2 min_latency max_latency
>   { failures | serialization_failures deadlock_failures } [ sum_lag sum_lag_2 min_lag max_lag [ skipped ] ] [ retried retries ]
> 
> Note that before it was like this:
> 
> interval_start num_transactions​ sum_latency sum_latency_2 min_latency max_latency​ [ sum_lag sum_lag_2 min_lag max_lag [ skipped ] ]
> 
> So newly added items are "{ failures | serialization_failures deadlock_failures }" and " [ retried retries ]".
> 
> > TBH, I think the *real* problem is that the complexity of this log format
> > has blown past "out of hand".  Can't we simplify it?  Who is really going
> > to use all these numbers?  I pity the poor sucker who tries to write a
> > log analysis tool that will handle all the variants.
> 
> Well, the extra logging items above only appear when the retry feature
> is enabled. For those who do not use the feature the only new logging
> item is "failures". For those who use the feature, the extra logging
> items are apparently necessary. For example if we write an application
> using repeatable read or serializable transaction isolation mode,
> retrying failed transactions due to srialization error is an essential
> technique. Also the retry rate of transactions will deeply affect the
> performance and in such use cases the newly added items will be
> precisou information. I would suggest leave the log items as it is.
> 
> Patch attached.

Even applying this patch, "make postgres-A4.pdf" arises the warning on my
machine. After some investigations, I found that previous document had a break
after 'num_transactions', but it has been removed due to this commit. So,
I would like to get back this as it was. I attached the patch.

Regards,
Yugo Nagata


-- 
Yugo NAGATA