This mSQL Frontend is capable of administrating a kind of distributed DBMS. Vita l to a distributed DBMS is the offering of the transaction facility, and recover ing af deadlocks. This mSQL-application is capable of this.
It works by placing a local server - 'jebd' - between local and remote msql2d's, and all mSQL applikations at all sites. All the 'jebd' servers is coordinated w ith respect to accessability on concurency by a central lockmanager.
The frontend is an addon to mSQL by David Hughes (http://www.hughes.com.au), a s ingle threaded SQL database server which runs on diffent platforms. This Fronten d is developted under release 6.0 of Redhat Linux 2.2.5, by use of egcs 2.91.66 c++ compiler. A selfcontained part of the Frontend, a server component called th e Lockmanager, is written as a Perl script.
It builds on a Transaction Manager (TM) and a Lock Manager (LM). The LM is loose ly based on the centralized 2-phase lock manager (C2P-LM) described in 'Distribu ted Database Systems 2nd. Ed.' by Özsu and Valduriez.
We have taken the liberty though to give our LM a bit more responsebility. It ma nages the locks as expected, but at the same time it maintains data on the table s location based on data from the TMs. It also divides the Id between the TMs to keep these unique.
We have taken the liberty though to give our LM a bit more responsebility. It manages the locks as expected, but at the same time it maintains data on the tables location based on data from the TMs. It also divides the Id between the TMs to keep these unique.