Streaming Rep Lab Part 2 – recap

We had our Streaming Rep Lab followup last night1. It was mostly successful: half of the new people got it up & running, and the people who’d been at the previous workshop got to experiment with almost everything on the agenda.

The cheatsheet is up on our git repo: https://github.com/pdxpug/cheatsheets 2.

We talked a bit about monitoring and messed around with some of the available functions (e.g. pg_last_xact_replay_timestamp), started looking at pg_xlogdump (for “educational purposes”, of course), checked out a packet capture between the master & standby, and finished up with breaking the link between the master & the standby: the standby cried a bit about not being able to reach the master, but as soon as we restored the link, everything was fine.

The overarching theme of the evening is that we need to come up with a more robust plot to make Postgres fail in an interesting way.

SELECT pg_last_xact_replay_timestamp(); will give you a WAL ID, but is only valid on a standby.
The function to translate it to a file name: SELECT pg_xlogfile_name([id]); can only be run on the master. So that’s kinda weird and requires some puzzling out.

I started a wiki page of ideas for future labs, but we may be hung up on streaming rep & breaking it for a little while 🙂

Thanks to Emma for hosting & providing dinner!



1 – With a puppy.
2 – Yes, I know there is something wrong with the step numbering. It renders correctly in github’s md validator, but not when I upload it.

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Streaming Rep Lab, Part 2 – two weeks from today

When: Thu Feb 27, 6pm-9pm (light dinner provided)
Where: Emma, B-side 6 Building, 5th floor

This is in addition to our regular monthly meeting, which is next week.

We didn’t quite get everything covered last time, so we’re having a followup lab to:
– practice recovery (which means we’ll be breaking it 🙂 )
– discuss monitoring options
– check out the human-readable WAL

You are welcome to attend if you couldn’t make the first lab. We’ll have a quick review of what we did, but won’t be spending too much time on it. As with the previous lab, there is no set schedule or exercises – we’ll make it up as we go.

Please come prepared with a laptop with the SR setup of your choice. Bonus points if it’s broken and we need to troubleshoot it. (SR, not your hardware.)

Space is limited, so please sign up in advance:

PDXPUG: February meeting

When: 7-9pm Thu Feb 20, 2014
Where: Iovation
Who: Dave Kerr
What: Monitoring Postgres at New Relic

You already know that New Relic can give you really good insight into your
applications. But how about your PostgreSQL database?

Join Dave Kerr as he shows that New Relic isn’t just for developers anymore!
We’ll demo using New Relic’s system monitoring along with its plugin system
where you can get in-depth database information such as slow queries,
number of backends, checkpoint info – just about everything a DBA needs!

Dave Kerr is a recovering DBA, PostgreSQL evangelist and is currently working
as a Software Engineer on the Site Engineering team at New Relic.

Our meeting will be held at Iovation, on the 32nd floor of the US Bancorp Tower at 111 SW 5th (5th & Oak). It’s right on the Green & Yellow Max lines. Underground bike parking is available in the parking garage; outdoors all around the block in the usual spots. No bikes in the office, sorry!

Building security will close access to the floor at 7:30.

See you there!