When setting up an Oracle database to work with Axapta it is often (normally) configured as a dedicated database server for the following reasons:

· Until now this has been the default behavior of an Oracle database.

· Early versions of the multithreaded server was known to be unstable and with some annoying bugs.

The backside of configuring the database as a dedicated server is:

· Each new database connection creates a process / thread on the server.

· Each new database connection allocates more memory for PGA purposes than a similar multithreaded connection.

As you increase the number of concurrent users in an Axapta system you will also increase the administrative burden of the Oracle database server, because you will start new processes / threads on the database server for each new Axapta session. At one point this task of switching between processes / threads will be so overwhelming big part of the servers activity that it will “kill performance” on the server.

Large Oracle Axapta installation with several hundred concurrent Axapta session are therefore more or less forced to configure their database as a multi threaded server.

Axapta running in 2-tier mode has in average 3-4 database connection, which is why configuring your Oracle database as multithreaded will ease the database servers tasks of administer the processes / threads and decrease the consumption of memory. Even though Axapta in 2-tier mode is more expensive database connection wise compared to 3-tier mode you will still benefit from using multithreaded server when running Axapta in 3-tier mode.

This document describes in short how to your Oracle database as a multithreaded server.

1. Oracle init.ora parameters

If you want to understand the way a multithreaded server works compared to a dedicated server, then you can read about this in the following 2 Oracle manuals:

· Oracle Concepts

· Oracle Administrator guide

The following Oracle kernel parameters must or can be specified in order to make the Oracle database server run in multithreaded server mode. A detailed description of these parameters can be found in the “Oracle Reference” manual.

Parameters  
mts_dispatchers:   Controls the protocol and number of dispatcher processes started at instance start. In the most simple way you just specify the protocol and the number of dispatcher processes stated at instance start:
·    mts_dispatcher=”(protocol=<protocol>)(dispatchers=<n>)”

<protocol> would typically be TCP and <n> is the number of dispatchers. You can specify multiple MTS_DISPATCHERS in the initialization file, but they must be adjacent to each other.

To specify that you want to start 5 dispatchers for the TCP/IP protocol at instance start you must specify as follows:
·    mts_dispatcher=”(protocol=TCP)(dispatchers=5)”

mts_max_dispatchers:  Specifies the maximum number of dispatcher processes allowed to be running simultaneously. Default: 5 or the number of dispatchers configured, whichever is greater. For most systems, a value of 200 – 250 connections per dispatcher provides good performance.
mts_servers :  Specifies the number of server processes that you want to create when an instance is started up. If system load decreases, this minimum number of servers is maintained. Therefore, you should take care not to set mts_servers too high at system startup.
mts_max_servers:   Specifies the maximum number of shared server processes allowed to be running simultaneously. If artificial deadlocks occur too frequently on your system, you should increase the value.
Default: Derived from mts_servers (either 20 or 2*mts_servers) .
Tests in out benchmark lap shows that in order to avoid artificial deadlocks in a 3-tier environment you should specify mts_max_servers as 1.2 * Number of active Axapta sessions. If you have 500 concurrent Axapta sessions, then you should specify mts_max_servers to be 600.
instance_name :  Name of the instance. Default value is the instance’s SID. NB! Due to a bug in Oracle 8.1.7 you must specify this parameter in order to run multithreaded server.

2. Start of multithreaded database environment

After you has changed the Oracle initialization parameters in your init.ora file, then you must bounce the database (shutdown and start again). This you have to do to let the dispatcher processes be registered by the listener process and thereby start the database as multithreaded. When running a multithreaded database you must always start the listener processes before you start the database. If the database is started before the listener, then the database will start the dispatcher processes, but because the listener don’t know their existence the database will run as a dedicated server.

Check in your alert log for your database that the dispatchers has started. Just after the start banners of the database and non-default system parameters you should find 2 lines looking something like this:

starting up 5 shared server(s) …

starting up 2 dispatcher(s) for network address ‘(ADDRESS=(PARTIAL=YES)(PROTOCOL=tcp))’…

To make sure that the listener has registered the dispatcher processes correctly start the listener control utility and list services supported by the listener (bold text indicates the commands you have to execute):

C:\>lsnrctl

LSNRCTL for 32-bit Windows: Version 8.1.7.0.0 – Production on 14-MAY-2001 12:37:27

(c) Copyright 1998 Oracle Corporation. All rights reserved.

Welcome to LSNRCTL, type “help” for information.

LSNRCTL> set password oracle

The command completed successfully

LSNRCTL> services

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=wk0-kma-dev-nt4)(PORT=1

21)))

Services Summary…

AXDB has 3 service handler(s)

DEDICATED SERVER established:0 refused:0

LOCAL SERVER

DISPATCHER established:0 refused:0 current:0 max:1022 state:ready

D001 <machine: WK0-KMA-DEV-NT4, pid: 338>

(ADDRESS=(PROTOCOL=tcp)(HOST=wk0-kma-dev-nt4.intern.dd.dk)(PORT=1196))

DISPATCHER established:0 refused:0 current:0 max:1022 state:ready

D000 <machine: WK0-KMA-DEV-NT4, pid: 337>

(ADDRESS=(PROTOCOL=tcp)(HOST=wk0-kma-dev-nt4.intern.dd.dk)(PORT=1195))

The command completed successfully

In the case above is the listener named “listener” (the default value) and there is no database explicit specified in the listener SID_LIST_<listener> in the listener.ora file.

To check that the connection is established in shared mode you can query services again and check if the established counter for one of the dispatchers has been increased.
The listener.ora file used in the above shown example look like:

# LISTENER.ORA Network Configuration File: D:\ORACLE\NETWORK\ADMIN\listener.ora

# Generated by Oracle configuration tools.

LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS = (PROTOCOL = TCP)(HOST = wk0-kma-dev-nt4)(PORT = 1521))

)

(DESCRIPTION =

(ADDRESS = (PROTOCOL = IPC)(KEY = WK0KMA))

)

)

PASSWORDS_LISTENER= (oracle)

From Axapta point of view you don’t have to change anything to utilize the new setup at the database unless you for some reason wants to connect to the database in dedicated mode. To do so you have make a new entry in your tnsnames.ora file where you (SERVER=DEDICATED) in your CONNECT_DATA section for that entry.

AXDBTCP.WORLD = (DESCRIPTION =

(ADDRESS_LIST =

(ADDRESS = (PROTOCOL = TCP)(Host = dbserver)(Port = 1521))

)

(CONNECT_DATA = (SID = AXDB)(SERVER=DEDICATED))

)

Be aware that for Oracle databases running on a Windows server is TCP/IP the only supported protocol for multithreaded connections.

Axapta system tables contain data that the Axapta kernel uses to control the behaviour of the kernel.  Axapta system tables are created automatically by the kernel, when Axapta is started for the first time against an empty database or after a service pack upgrade.

Axapta system tables are in many ways treated as ordinary Axapta tables from the kernel’s point of view. They are synchronized in same way and inserts / updates of the tables are done in a similar way.

System tables are not company specific and do not have a “DataAreaId” column.  Therefore, system tables are implicitly treated as if they belong to the “DAT” company.

All system tables (except “SqlSystemVariables”) have a “RecId” column, which is updated as an ordinary table belonging to the “DAT” company.

Some system tables has the following standard columns:

·         MODIFIEDDATE

·         MODIFIEDTIME  

·         MODIFIEDBY    

·         CREATEDDATE   

·         CREATEDTIME   

·         CREATEDBY

All system tables (except “SqlSystemVariables”) have a TableId.  The TableId’s for system tables starts at 65508 and each field in a system table also has a Id that follows the normal rules for Id generation of FieldId’s.  Please refer to the form “SysSqlDictionary” to see the mapping of system tables and TableId / FieldId.

Axapta system tables can’t be accessed or viewed directly from the AOT (Axapta Object Tree).  Furthermore, you should not access the system tables Axapta application layer.

This document contains a description of the most important Axapta system tables, except the table “SqlSystemVariables” which is described in another document. The information in this document is not valid for the table “SqlSystemVariables”.

Description of Axapta System Tables

ACCESSRIGHTSLIST (TableId = 65526)

This table contains info about explicit granted access rights for the defined user groups.

Note: Until you have explicitly defined permissions for a table, access to tables is defined using Feature keys. Once you set restrictions on a particular table for a particular user group, all other groups automatically have No Access to that table. As this will seriously impact the way the system works, you are presented with a warning dialogue before any change takes effect. In the dialogue you must decide whether other user groups should have no access as the result of the change you are making, or if other groups should keep their present permissions.

COMMON

COMPANYDOMAINLIST (TableId =  65509)

This table contains relation between companies and domains.

DATAAREA (TableId = 65533)

This table contains data about created companies.

DATABASELOG (TableId = 65508)

This table contains data about which tables and events to log. The events are logged in the Axapta table SysDatabaseLog.

DOMAININFO (TableId =  65510)

This table contains data about domains.

PRINTJOBHEADER (TableId = 65525)

This table is used in connection with printing from Axapta.

PRINTJOBPAGES (TableId = 65524)

This table is used in connection with printing from Axapta.

SQLDESCRIBE (TableId = 65527)

This table is used temporarily during check / synchronisation process and should normally be empty.

SQLDICTIONARY (TableId = 65518)

This table contains data dictionary data about Axapta application and system tables (except SqlSystemVariables) as stored in Axapta data dictionary. Content of this table can be viewed by the form “SysSqlDictionary”

SQLPARAMETERS (TableId = 65517)

This table is for future use.

SQLSTATISTICS (TableId = 65513)

This table is for future use. It is planned to store Axapta specific statistic data, which can help the kernel to optimize the parse, bind, execute and fetch operations.

SQLSTORAGE (TableId = 65515)

This table contains Oracle storage parameters as specified in Axapta “Storage Setup” utility. The value are added to the CREATE statement, whenever a database object is created from Axapta.

SQLSYSTEMVARIABLES

The SQLSystemVariables table is not viewable from with Axapta; however, you can look at the contents by looking at the Database Information form.
SYSCONFIG (TableId = 65514)

This table contains license information, version, feature key setup and other basic system configuration data.

SYSLASTVALUE (TableId = 65528)

This table is used to store set values for specific program elements for individual users, which should survive from session to session.  This table is used by both the kernel and the application.

SYSTEMRECORDLEVELSECURITY (New for version 3.0)

This table contains info about record level security based on table, user and company. The stored information is the extra where condition for the table.

SYSSEMAPHORE

This is a virtual system table that is created and maintained by the kernel. The table can’t be found on the database; however, it contains data about all kernel semaphores

SYSTEMSEQUENCES (TableId = 65516)

This table contains sequence numbers for RecId and TransactionId. A row for each used company and sequence.

TABLECOLLECTIONLIST (TableId = 65532)

This table contains data about relation between virtual companies and table collections

USERGROUPINFO (TableId = 65530)

Table contains name for the defined user groups

USERGROUPLIST (TableId = 65529)

Table describes relation between users and user groups.

USERINFO ((TableId = 65531)

Table is used to store general set up values for individual users. Use the “Tool/Options..” menu-item  to change values in this table. If “UserInfo” is empty or entry for current user doesn’t exists, then no menu item or toolbar is available from Axapta. 

UTIL*  (UTILAPPLHELP, UTILCODEDOC,  UTILELEMENTS,  UTILELEMENTSOLD,  UTILIDELEMENTS, UTILIDELEMENTSOLD, UTILLOCKS)

These are all virtual tables containing info about programming elements.

VIRTUALDATAAREALIST (TableId = 65534)

This table contains data about relation between real companies and virtual companies.