24. 09. 2020.

How to setup Adobe Flash Support in Browser for Linux

Some vendors still relies on Adobe Flash for rich web contents. One such example is Oracle, where you can find that all tuning reports are generated by using Flash. Even Oracle Enterprise Manager Grid, main Oracle monitoring tool still uses Adobe Flash to generate its content. If you are on Windows, you can use Internet […]

10. 05. 2020.

Customer experience on Oracle Db – One metric to rule them all

Over the years I’ve found that almost every enterprise monitoring software I’ve been working with so far (and there are a few dozen of them), put extensive load on targets under the monitoring. While one monitoring tool brings extensive hard parsing on its targets, another one calculates free space for each tablespace in a very […]

20. 01. 2020.

Configuring environment for debugging PL/SQL Stored procedures

Main objective of this post is to list some of the typical issues I’ve found when debugging PL/SQL stored procedures, functions and packages. There are many ways of how you can debug server side code, and here is the list of the most common ways I’ve found in practice: dbms_debug_jdwp dbms_debug dbms_output database tables used […]

07. 01. 2020.

Oracle database links – performance impact

In this post I’m going to explain the most important drawbacks when using db links technology for purposes for which it is not design for. To be more precise, the case in which db links are used to massively exchange data between many separate databases will be explained. In the previous post you can find […]

21. 10. 2019.

Performing stress test against Oracle database that is running in a Cloud

Today majority of enterprises are moving or at least considering moving some load into the Cloud. What you need to be aware in such case, system requirements for a Cloud load are quite different when comparing with on-premises, mainly due to many new moving parts that are not present within classical environment such as sharing […]

05. 09. 2019.

Reducing CPU consumption and Oracle licenses by fixing context switching in Oracle Db

Context switching is one of the most overlooked topics when tuning the Oracle database, as you can’t simply see it directly (e.g. “context switching” wait event doesn’t exist). Instead you should use indirect approach  (through the increased CPU consumption), as it’s recorded as a CPU wait event. Context switching what it is and what impact […]

26. 02. 2019.

Impact of the JVM Garbage Collector on the realistic workload

At the last regional Java and Open Source conference where I held the presentation named: “Java Mission Control now in OpenJDK – best practice”, several questions have been raised about a way of testing JEE apps, influence of a GC (Garbage Collector) on the overall performance, new GC engines etc. With OpenJDK 11 we have […]

05. 02. 2019.

OpenJDK Mission Control – how to install it properly

If there is one tool that have almost all what is needed for monitoring, troubleshooting and tuning Java apps, that will be OpenJDK Mission Control. There are several reasons why JMC will be hot topic in Java events from now on: More than 95% of all issues related to JVM, application servers, deployed apps and […]

04. 01. 2019.

Multipath I/O and Network bonding

Event though Multipath I/O and NIC bonding is more related to sysadmin and storage admin tasks, it is good idea to grab some knowledge about those keywords as they play important role in achieving good performance. In the series of articles about disk speed I explained why it is good to know what values you […]

21. 12. 2018.

How to quickly check disk(s) speed limit on Linux – part 3

This is the third part of a series of articles about measuring performance of disk subsystem. In the first part you can find details of how to measure disk performance by using dd command: https://www.josip-pojatina.com/en/how-to-quickly-check-disks-speed-limits-on-linux/ while in the second part you can find similar information by using the hdparm utility: https://www.josip-pojatina.com/en/how-to-quickly-check-disks-speed-limit-on-linux-part-2/ In this blog I’ll […]