Aurora MySQL synch/mutex/innodb/aurora_lock_thread_slot_futex wait

Thanks to Jeremiah Wilton for the following info:

This wait event indicates that there is a thread which is waiting on an InnoDB record lock. Check your database for conflicting workloads. More information on InnoDB locking can be found here: https://dev.mysql.com/doc/refman/5.6/en/innodb-locking.html

 

In other words, record-level lock conflicts are happening. More than one connection is trying to update the last_login for a particular id in the_table at the same time. Those (more...)

Is NFS on ZFS slowing you down?

If you think so, check out shell script “ioh.sh” from github at  https://github.com/khailey/ioh

Introduction and Goals

The goal of ioh.sh is to measure both the throughput and latency of the different code layers when using NFS mounts on a ZFS appliance. The ZFS appliance code layers inspected with the script are I/O from the disks, ZFS layer and the NFS layer. For each of these layers the script measures the throughput, latency and (more...)

IP CIDR rules and address ranges

I always forget IP address range coverage rules and forget where to look.

It’s the wiki!

and for good reference here is the table:

https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

 

Screen Shot 2017-11-03 at 11.28.31 AM

Best method for tuning sub-optimal execution plans

How do you determine if the Oracle SQL optimizer has created a sub-optimal execution plan? re-run statistics and see what happens? wait for Oracle to fin other execution plans? What if neither method is helping? Do you read the execution plan? What do you look at? Differences in actual vs estimated? How successful is that? Look for full table scans?  Do you look at the 10053 trace? How much time and effort does that take?  (more...)

Oaktable World 2017 @ Oracle Open World

 

http://www.oaktable.net/blog/oak-table-world-2017-oracle-open-world

The Oak Table members will be discussing their latest technical obsessions and research on Monday and Tuesday, (Oct. 2nd and 3rd, 2017).  The truth is, folks-  The Oak Table experts are an AWESOME group, (if I don’t say so myself! :)) as we could have easily done another day of incredible sessions, but alas, two days is all we have available for this year’s event.

 

Screen Shot 2017-09-29 at 11.10.53 AM

Screen Shot 2017-09-29 at 11.11.04 AM

benchmarking your disks

 

While at Delphix, we did a lot of storage benchmarking. The I/O response times of Delphix depends, as one would logically imagine, heavily on the underlying disks. Sure Delphix can cache a lot ( with 1 TB of ram and 3x compression that’s 3TB and that 3TB can be shared by 10 or a 100 copies being the equivalent to 30TB or 300TB of databases) but really there will always be important I/O coming (more...)

Postgres monitoring script pgmon.sh

Screen Shot 2017-03-09 at 8.13.35 AM

photo by Thomas Hawk

https://github.com/khailey/pgmon

$ ./pgmon.sh 
Usage: pgmon.sh [username] [password] [host] <sid=postgres> <port=5432> <runtime=3600>

$ ./pgmon.sh kyle kyle  mymachine.com

  psql -t -h mymachine.com -p 5432 -U kyle postgres < /tmp/MONITOR/tmp/mymachine.com:postgres_collect.pipe &

  RUN_TIME=-1
  COLLECT_LIST=
  FAST_SAMPLE=wts
  TARGET=mymachine.com:postgres
  DEBUG=0

  Connected, starting collect at Wed Mar 8 12:05:12 PST 2017
  starting stats collecting
  SET

  AAS| blks_hit | blks_read | tup_returned | tup_fetched | tup_inserted | tup_updated | tup_deleted  

    (more...)

Example Jmeter workload for Postgres and Oracle

pgload.jmx is JMX file you can load into Jmeter and run a substantial load on a Postgres database. Should work just as well on Oracle if you change the test SQL from “Select 1″ to “select 1 from dual”

Install jmeter on our machine . On my mac, I did

  • brew install jmeter

You will need the Postgres driver. I used

9th Circuit Court Ruling 3-0

Little did I know this building that captured my visual attention and imagination so many times walking to work over the last 6 months would play a historic roll in the current political climate.

Here is a picture of the US District Court House from recent articles

Screen Shot 2017-02-11 at 9.19.43 PM

 

And here are some of my iPhone shots over the last few months with some Instagram filtering mixed in :)

Screen Shot 2017-02-10 at 8.17.09 AM Screen Shot 2017-02-10 at 8.15.09 AM

Screen Shot 2017-02-10 at 8.15.01 AMScreen Shot 2017-02-10 at 8.16.58 AM Screen Shot 2017-02-10 at 8.16.52 AM Screen Shot 2017-02-10 at 8.16.21 AM Screen Shot 2017-02-10 at 8.15.54 AM Screen Shot 2017-02-10 at 8.14.32 AM Screen Shot 2017-02-10 at 8.14.24 AM Screen Shot 2017-02-10 at 8.14.17 AM Screen Shot 2017-02-10 at 8.14.09 AM Screen Shot 2017-02-10 at 8.13.59 AM Screen Shot 2017-02-10 at 8.13.41 AM Screen Shot 2017-02-10 at 8.13.32 AM Screen Shot 2017-02-10 at 8.13.18 AM

jmeter – Variable Name must not be null in JDBC Request

So Jmeter seems super cool.

I’ve only used it a little bit but it does seem a bit touchy about somethings (like spaces in input fields) and the errors are often less than obvious and I’m not finding that much out there on google for the errors.

Today I ran into the error

Variable Name must not be null in JDBC Request

 screen-shot-2017-01-06-at-12-01-10-pm

screen-shot-2017-01-06-at-12-00-50-pm

and Googling it didn’t turn up anything.

I’m pretty sure I ran (more...)