Monthly Archives: May 2020


Region, AZ, data center

A region has minimum 2 data centers.

Data center is physical location. 2 data centers are physically isolated.

Each AZ is backed by 1 or more data centers.

Abstracting things further, to distribute resources evenly across the zones in a given region, Amazon independently maps zones to identifiers for each account. This means the us-east-1a availability zone for one account may not be backed by the same data centers as us-east-1a for another account.

2 AZ within a region can talk to each other through private link in a fast way.

Java version switch

# Add below in ~/.zshrc
export JAVA_HOME=`/usr/libexec/java_home -v 1.8`
export JAVA_HOME=`/usr/libexec/java_home -v11`

# Check java version
/usr/libexec/java_home -v 11


jenkins start/stop

Create Jenkins pipeline with Freestyle project