Tag: Troubleshooting
-
Building an Apache Spark Performance Lab: Tools and Techniques for Spark Optimization
Building an Apache Spark Performance Lab: Tools and Techniques for Spark Optimization Apache Spark is renowned for its speed and efficiency in handling large-scale data processing. However, optimizing Spark to achieve maximum performance requires a precise understanding of its inner workings. This blog post will guide you through establishing a Spark Performance Lab with essential
-
Apache Spark 3.0 Memory Monitoring Improvements
Apache Spark 3.0 Memory Monitoring Improvements TLDR; Apache Spark 3.0 comes with many improvements, including new features for memory monitoring. This can help you troubleshooting memory usage and optimizing the memory configuration of your Spark jobs for better performance and stability, see SPARK-23429 and SPARK-27189. The problem with memory Memory is key for the performance
-
Linux BPF/bcc for Oracle Tracing
Linux BPF/bcc for Oracle Tracing Topic: In this post you will find a short discussion and pointers to the code of a few sample scripts that I have written using Linux BPF/bcc and uprobes for Oracle tracing. Previous work and motivations Tools for dynamic tracing are very useful for troubleshooting and internals investigations of Oracle
-
How to generate subset out of Real Application Testing captures
How to generate subset out of Real Application Testing captures I’ve already mentioned on this blog very useful Consolidated Database Replay feature, for example while testing unified auditing performance impact (http://db-blog.web.cern.ch/blog/szymon-skorupinski/2014-06-unified-auditing-performance) or while investigating problems with hanging workload capture (http://db-blog.web.cern.ch/blog/szymon-skorupinski/2014-06-starting-workload-capture-hangs-it-really-problem-rat). But only recently I’ve found that along with this functionality, there was additional and again
-
Extended Stack Profiling – Ideas, Tools and Comments
Extended Stack Profiling – Ideas, Tools and Comments Topic: This post provides a short summary and pointers to previous work on Extended Stack Profiling for troubleshooting and performance investigations. Understanding the workload is an important part of troubleshooting activities. We seek answers to questions like: what is the system doing, where is the time spent,
-
XFS on RHEL6 for Oracle – solving issue with direct I/O
XFS on RHEL6 for Oracle – solving issue with direct I/O Recently we were refreshing our recovery system infrastructure, by moving automatic recoveries to new servers, with big bunch of disks directly connected to each of them. Everything went fine until we started to run recoveries – they were much slower than before, even though
-
How to create your own Oracle database merge patch
How to create your own Oracle database merge patch A little bit scary title, isn't it? Please keep in mind that definitely it is neither supported nor advised method to solve your problems and you should be really careful while doing it – hopefully not on production environment. But it may sometimes happen that you
-
Oracle 12c – causing problem by solving it!?!
Oracle 12c – causing problem by solving it!?! Regular readers of our blog probably already know that for most of our databases we’re using two storage layers to keep our backups – NAS volumes as a primary layer and tapes as secondary one – please check “Datafile without backups – how to restore?” for more
-
Nuances of Oracle Managed Files (OMF) and RMAN
Nuances of Oracle Managed Files (OMF) and RMAN Oracle Managed Files (OMF) have many advantages, but the fact that such files could coexist in the same database with manually added (and named) ones, could sometimes lead to confusion. Situation is made worse by the fact, that there is no straightforward way (at least of which
-
Which shared memory segments belong to my database instance?
Which shared memory segments belong to my database instance? I’ve already described how important is to test your backup strategy and restore/recovery procedures, but while doing so, you could of course encounter some problems, not really related with the recoverability as such. Recently, we’ve got such a problem on our recovery server, at the very