At some point my RHEL7 development virtual machine run out of space. Resizing the image is really made easy by RedHat: STEP 1: Resize the virtual machine disk [root@localhost VMs]# qemu-img resize RHEL7-clone.qcow2 50G Image resized. [root@localhost VMs]# STEP 2: Start the VM and check the disks from inside the VM Check the virtual disk:… Read More »
The requirement that an enterprise system has high availability on site and across sites is very often encountered in the world of financial systems. To achieve this requirement the obvious solution is to have a cluster on the primary site (PR) and another cluster on the disaster recovery site (DR). On the PR we created… Read More »
My setup becomes more and more complicated bellow there are the updated steps of my configurations with references to the original posts containing the partial configurations. STEP 1 EdgeRouter : Dual WAN with Hair Pin Initially I started with a dual-wan configuration with some extra setting to exclude from load balancing the hair pin connections:… Read More »
I wanted to use for my site-to-site VPN connection some aliases in the configuration files. The simple solution was to configure some dynamic DNS aliases with afraid.org After creating an account and defining a site name like site1.mooo.com do the following from CLI configure set service dns dynamic interface eth0 service afraid host-name site1.mooo.com set… Read More »
As a result of setting up my site-to-site VPN see this it is much easier to transfer things from one site to the other. The questions that came to mind were: What is the bandwidth of my VPN ? What is the limiting factor ? My ISPs or the Edge Router ? To answer to… Read More »
I have two sites hosting my home servers so I wanted a solution to have a permanent link between the sites. On site one I have an EdgeRouter POE and on the other site an EdgeRouter Lite and the obvious solution is to have a site to site VPN on a permanent basis. There is… Read More »
Sometimes working with Hibernate you get the following error in case a persist is executed on an object with dependencies. com.ibm.db2.jcc.am.SqlIntegrityConstraintViolationException: Error for batch element #1: The insert or update value of the FOREIGN KEY “INST1.MESSAGE.FK_1FUTL48XT47HPPGH0YXQM1MIJ” is not equal to any value of the parent key of the parent table.. SQLCODE=-530, SQLSTATE=23503, DRIVER=4.13.127 From IBM… Read More »
Sometimes things go slow in the database even if the original setup was done with a lot of care. The data traffic the usage of the application can sometimes impose the need of extra indices in addition to the original indices added by the enterprise application client that uses the Oracle database. The following procedure… Read More »
Microsoft SQL Server Standard Edition has a great feature present in this basic license: Database Replication in Synchronous mode. To activate the database replication of a database from Primary Site (PR) to Disaster Recovery Site (DR) where the database to be replicated is called myDB the following simple steps must be performed: On PR site… Read More »
Snapshot isolation is a guarantee that all reads made in a transaction will see a consistent snapshot of the database. The transaction itself will successfully commit only if no updates it has made, conflicts with any concurrent updates made since that snapshot. By using it, deadlock situations when a read operation (intense resource consuming operation)… Read More »