Author Archives: George Valentin Voina

RedHat/Fedora Linux NIC bonding

By | February 9, 2017

Red Hat Enterprise Linux allows administrators to bind multiple network interfaces together into a single channel using the bonding kernel module and a special network interface called a channel bonding interface. Channel bonding enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy. The behaviour of the bonded… Read More »

Oracle: Get the real size of a table with blobs

By | February 8, 2017

As we now in case of a table with BLOBs in the actual table row only a reference to the BLOB is stored. In order to get the real table size of my table ‘MY_BLOB_TABLE’ including the refereed BLOBs the following query holds in Oracle: SELECT sum( bytes)/1024/1024 size_in_MB FROM user_segments WHERE (segment_name = ‘MY_BLOB_TABLE’… Read More »

Oracle: Resolve blocking processes

By | February 8, 2017

Sometimes an oracle query goes nuts and blocks the DB. To find the blocked processes started by user MYUSER execute: SELECT s.inst_id, s.sid, s.serial#, p.spid, s.username, s.program FROM gv$session s JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id where s.username like ‘MYUSER’; To kill the blocking process: ALTER SYSTEM KILL SESSION ‘sid,serial#’

DB2: Inline LOBS

By | February 8, 2017

LOBS is the DB2 way of dealing with big data. In db2 you can have a table that contains a column defined as LOB where one can dump large binary data (images, compressed text files, video or audio). The problem is the way this LOBS are stored by DB2. By default they are stored “offline”… Read More »

Migrate Windows 10 to SSD

By | January 25, 2016

My desktop Dell XPS 8700 is a beast even after more than 2 years of the official release. The problem with it is that in a typical big corporate fashion it contains an unbalanced set of hardware: * A very fast processor * 16GB of memory (4x4GB so not so up-gradable to the 32GB maximum)… Read More »

DB2: Limit an UPDATE/DELETE query in DB2

By | February 8, 2017

There are times when a simple UPDATE or DELETE cannot be used directly on the database due to the huge amount of data stored in the table. We already covered the topic of increasing the transaction log, see post, but sometimes this is not enough. In the cases when too much data is going to… Read More »

HP Microserver Gen8 compatibility list

By | January 28, 2021

As a big fan of the HP Microserver Gen8 (I own 3 of them in two locations) I compiled my own list of compatible hardware that I am using or used in building the servers.I have to thank the good fan forums that I always consult previous of buying new hardware for my HP Microservers… Read More »

DB2: (SQL Error: -30090) caused by XA access to a nickname to a federated database

By | February 8, 2017

In a setup having an enterprise application depending on a database instance where some tables are defined as nicknames to tables from a federated database, it can happen to get this very cryptic DB2 error. [12/10/15 18:06:54:895 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions SQL Error: -4229, SQLState: null [12/10/15 18:06:54:903 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper… Read More »

#DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6

By | May 26, 2017

1 General Considerations Our example enterprise applications run on a Linux Cluster with a shared cluster storage resource. Having this HA setup ensures that we have a high rate of service availability on the production site. To ensure that the disruption time in service of our enterprise application is minimal as possible the best solution… Read More »

Disable SSL3 in Glasshfish

By | May 26, 2017

As we know there are big security concerns about the use of SSL3 so a lot of security audits are demanding it to be disabled in all applications that are exposed with a WEB GUI. Disabling SSL3 can be done via the admin console. First SSL is disabled individually on the HTTP listeners of your… Read More »