Oracle Database: Process RSM0, PID = , will be killed

Oracle Database: Process RSM0, PID = , will be killed

DGBroker Vineet Sachdeva   September 06, 2019

When you check status of database using dgmgrl and you get the error message in alert log - 
'Process RSM0, PID = 1524144984, will be killed'

that means that dgmgrl is not able to get the response within stipulated amount of  time. 
This can be because of many reasons such has high CPU, Load Average , network etc. 


So, what you can do is increase the overall timeout period using 

'EDIT CONFIGURATION SET PROPERTY OperationTimeout=90'

another symptom of this is when you will check the database details, there will be no metrics which will be populated. 

Oracle Exadata: AIDE, Advanced Support Gateway and Exadata Image 19

Oracle Exadata: AIDE, Advanced Support Gateway and Exadata Image 19

Exadata Vineet Sachdeva   September 05, 2019

Oracle has released Image 19 and AIDE, however what they really missed is the platinum / advanced support gateway

the advanced support gateway is present as user orarom in directory /opt/OracleHomes

Now if you are getting daily alerts from AIDE complaining a lot of files have changed. 
Then look into the log file /var/log/aide/aide.log, you will find that the log files of agent are changed which are continously throwing the alerts 

What you need to do is add one line in the aide.conf file which is highlighted as below and then run exadataAIDE -u. 

This will ignore the directory and ensure no alerts are been sent. 


less aide.conf | grep opt
!/opt/OracleHomes

/opt/    CONTENT

AWS/Linux: How to know if a device has File system on it

AWS/Linux: How to know if a device has File system on it

Linux Vineet Sachdeva   September 04, 2019

It is a common question which comes to me from people to understand how to know if a raw disk has file system on it or not. 

There can be multiple ways but in this blog I will talk about file command

File command can help you know if the FS is there or not?
How 
use file -s '/device_name'
if you get output like data: that means no FS
If there is any other output, it means FS is present.

Amazon Web Services (AWS) : Placement Groups

Amazon Web Services (AWS) : Placement Groups

EC2 Vineet Sachdeva   September 03, 2019

In this blog, I am going to discuss an important new features which AWS has released which is called as placement groups. 

So, what are placement groups.
Placement groups are basically directives given to AWS Kernel to place your EC2 instances at specific locations. 
And what are these locations
- specific AZ
- specific RAC
- Zone based
and etc

So, As of now (Sep -2019), AWS has come up with 3 types of placement groups 

1. Cluster
2. Spread
3. Groups

Let's see what is what 

Cluster - Cluster Placement Group is basically a directive to launch EC2 instances within the same Rack.

Visualize thousands of servers placed in Amazon Data Centers and they are placed in different racks, so when you give 'Cluster' as placement group, all the instances will be launched within the same RAC (in same AZ).

Pros 

1. Great in terms of networking (10Gbps between 2 instances)
2. Gives low latency and high n/w throughput
3. Jobs such as Big data benefit 

Cons 
There is one big issue, if the RAC fails, you loose all the instances. 

Spread
Now visualize within all the data centers and you want to distribute your highly available application within multiple data centers, so spread helps you with that - with instances spanning multiple AZs and different physical RAC if in the same AZ.

Pros 

1. Reduced Risk in terms of failure
2. All the instances are on different physical hardware 
3. Provides High Availability for critical applications

Cons

1. You are limited to 7 instances per AZ per placement group. 

Partition

Within one AZ , span  multiple partitions, and what is partition, an isolation created by AWS in their data centers which is a physical boundary and ensures one partition's availability does not affects others. 

Pros

1. Instances do not share racks with other instances
2. Safe from partition failure
3. EC2 instance get access to partition information as metadata
4. Can spawn 100s of instances

Cons

1. The limitation put by AWS (as of now) is 7 partitions per AZ