Lately after one of the updates of docker binaries I started to have a strange issue in a Docker Swarm setup configured here. Services were no longer able to see each other if they were running on different nodes. If two services were running on the same swarm node there was no issue. This is… Read More »
In a perfect German tradition Conrad electronics shop released an Advent Calendar for Raspberry Pi. You can buy it online or from a Conrad shop if you get to go to Germany in a town with a Conrad shop. Got mine from the Conrad in Leipzig but online is available at Conrad Online There are… Read More »
“Invisible columns”: This is a new feature introduced in Oracle 12c that got me all excited.In short you can now have hidden columns in a table that are not visible to the standard SELECT, INSERT clauses if you do not want to. Some usage for this: Legacy application queries I hate how you have to… Read More »
The newest commodity this days is crowd sourced data. All the digital corporations push this envelope harder and harder. Google wants to make me a “local guide”: post images of places on google maps and review businesses for free of course (they give you a badge, you know like boy scouts badges). This is lately… Read More »
Sometimes you get a CA certificate in DER format and some application requires it in a PEM format. OpenSSL to the rescue: # openssl x509 -inform der -in myCA.der -out myCA.pem
One of the best articles about project management and software development Project management: A surefire way to kill your software product. As a software developer I have to agree with almost everything stated there and I can confirm most of it as true. You cannot treat creative people as resources and think that inspiration and… Read More »
At some point an increase in size of the replicated resource is needed. This can be caused by an increase in data retention times or an increase of transaction numbers affecting that resource. If the backing block devices can be grown while in operation (online), it is also possible to increase the size of a… Read More »
There is a very easy method of setting up on Linux an automatic back-up for Oracle by using database procedures, RMAN and scripts. STEP 1: Define a back-up script Create in /home/oracle/backup.sh a script file with the content: #!/bin/bash export ORACLE_HOME=/home/oracle/app/oracle/product/11.2.0/dbhome_1 export PATH=$PATH:$ORACLE_HOME/bin export ORACLE_SID=prod rman target / CMDFILE=/home/oracle/bin/backup.rman LOG /data/oradata/backuplogs/rman-`date -I`.log exit 0 Where… Read More »
Even when you think that you know something well enough you discover that there are some corner cases you never encountered. This is the main reason I like IT system administration tasks, you never get bored. This post is about one of this corner cases in a DRBD setup described in post #DRBD based disk… Read More »
CASE 1: If you use multi-stage docker builds you will end up with lots of un-tagged images. The proper way to clean the intermediary leftover images is: docker rmi $(docker images -f “dangling=true” -q) CASE 2: If you want to clean up all the old images for which you no longer have any instantiated container… Read More »