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18.3 As easy as 1…2…3

Well, finally it’s here! 18c for on-premise installation so the world can all get stuck into the cool new features of the latest release on their own laptops Smile  At least that is what I’ll be doing!

Naturally as soon as I heard the news, I downloaded the software and got ready to set aside the day for installation and creation of an 18c database. But I didn’t need that long – I didn’t need that long at all. Just a few clicks and a few commands and there it was – my 18c database up and running.

Check out how easy it is with my three videos.

Software Installation

Little things worth knowing: Creating a RAC One Node database on the command line

This post is going to be super short, and mostly just a note to myself as I constantly forget how to create a RAC One database on the command line. This post is for 12.2.0.1 but should be similar on 12.1 (although I didn’t test!).

Provided you are licensed appropriately, this is probably the most basic way how you create an admin-managed RAC One database on Linux for use in a lab environment:

OSWatcher, Tracefile Analyzer, and Oracle RAC 12.2

When I started the series about Tracefile Analyzer (TFA) I promised three parts. One for single instance, another one for Oracle Restart and this one is going to be about Real Application Clusters. The previous two parts are published already, this is the final piece.

The environment

I am using a virtualised 2-node cluster named rac122pri with nodes rac122pri1{1,2} based on Oracle Linux 7.4. RAC is patched to 12.2.0.1.180116. I installed a Grid Home and an RDBMS home (Enterprise Edition).

Real Application Clusters

Before starting this discussion it’s worth pointing out that TFA integration in RAC 12.2 works really well. TFA is installed as part of the initial setup of the binaries and documented in the Autonomous Health Framework.

Remote syslog from Linux and Solaris

Auditing operations with Oracle Database is very easy. The default configuration, where SYSDBA operations go to ‘audit_file_dest’ (the ‘adump’ directory) and other operations go to the database may be sufficient to log what is done but is definitely not a correct security audit method as both destinations can have their audit trail deleted by the DBA. If you want to secure your environment by auditing the most privileged accounts, you need to send the audit trail to another server.

Quick install of prometheus, node_exporter and grafana

This blogpost is a follow up of this blogpost, with the exception that the install method in this blogpost is way easier, it uses an Ansible playbook to do most of the installation.

1. Install git and ansible via EPEL:

# yum -y localinstall https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
# yum -y install ansible git

2. Clone my ‘prometheus_node_exp_grafana_install’ repository:

# git clone https://gitlab.com/FritsHoogland/prometheus_node_exp_grafana_install.git

3. Run the prometheus.yml playbook to install prometheus, node_exporter and grafana:

Oracle database wait event ‘db file async I/O submit’ timing bug

This blogpost is a look into a bug in the wait interface that has been reported by me to Oracle a few times. I verified all versions from Oracle 11.2 version up to 18.2.0.0.180417 on Linux x86_64, in all these versions this bug is present. The bug is that the wait event ‘db file async I/O submit’ does not time anything when using ASM, only when using a filesystem, where this wait event essentially times the time the system call io_submit takes. All tests are done on Linux x86_64, Oracle Linux 7.4 with database and grid version 18.2.0.0.180417

So what?
You might have not seen this wait event before; that’s perfectly possible, because this wait event is unique to the database writer. So does this wait event matter?

All about ansible vault

This blogpost is about using ansible vault. Vault is a way to encrypt sensitive information in ansible scripts by encrypting it. The motivation for this blogpost is the lack of a description that makes sense to me of what the possibilities are for using vault, and how to use the vault options in playbooks.

The basic way ansible vault works, is that when ansible-playbook reads a yaml file, it encounters $ANSIBLE_VAULT;1.1;AES256 indicating ansible vault is used to encrypt the directly following lines, it will use a password to decrypt it, and then uses the decrypted version in memory only. This way secrets can be hidden from being visible. Obviously, the password will allow decrypting it, and the password must be used in order for ansible-playbook to decrypt it.

The original use of vault is to encrypt an entire yaml file. As of Ansible version 2.3, ansible allows the encryption of single values in a yaml file.

A re-introduction to the vagrant-builder suite for database installation

In a blogpost introducing the vagrant builder suite I explained what the suite could do, and the principal use, to automate the installation of the Oracle database software and the creation of a database on a virtual machine using vagrant together with ansible and virtual box.

This blogpost shows how to use that suite for automating the installation of the Oracle database software and the creation of a database on a linux server directly, with only the use of ansible without vagrant and virtualbox.

A look into oracle redo, part 11: log writer worker processes

Starting from Oracle 12, in a default configured database, there are more log writer processes than the well known ‘LGWR’ process itself, which are the ‘LGnn’ processes:

$ ps -ef | grep test | grep lg
oracle   18048     1  0 12:50 ?        00:00:13 ora_lgwr_test
oracle   18052     1  0 12:50 ?        00:00:06 ora_lg00_test
oracle   18056     1  0 12:50 ?        00:00:00 ora_lg01_test

These are the log writer worker processes, for which the minimal amount is equal to the amount public redo strands. Worker processes are assigned to a group, and the group is assigned to a public redo strand. The amount of worker processes in the group is dependent on the undocumented parameter “_max_log_write_parallelism”, which is one by default.

A look into oracle redo: index and overview

I gotten some requests to provide an overview of the redo series of blogposts I am currently running. Here it is: