Starting and Stopping an Oracle CEP Server in a Multi-Server Domain
Administrating Multi-Server Domains With Oracle CEP Native Clustering 7-3
If one or more Oracle CEP servers in your multi-server domain on on different hosts, this element is mandatory if you plan to manage the multi-server
domain using the Oracle CEP Visualizer.
■
multicast-address: The multicast-address element is required unless all servers of the multi-server domain are hosted on the same computer; in
that case you can omit the multicast-address element and
Oracle CEP
automatically assigns a multicast address to the multi-server domain based on the computers IP address.
If, however, the servers are hosted on different computers, then you must provide an appropriate domain-local address. Oracle recommends you use an
address of the form 239.255.X.X, which is what the auto-assigned multicast address is based on.
All the
Oracle CEP
servers using this multicast-address must be on the same subnet.
■
identity: The identity element identifies the servers identity and must be an integer between 1 and INT_MAX.
Oracle CEP
numerically compares the server identities during multi-server operations; the server with the lowest
identity becomes the domain coordinator. Be sure that each server in the multi-server domain has a different identity; if servers have the same identity,
the results of multi-server operations are unpredictable.
■
enabled: By default the clustering of the servers in a multi-server domain is enabled for Oracle Coherence, so to enable
Oracle CEP
native clustering use enabledevs4jenabled.
Example 7–1 myServer1 config.xml File
config domain
namemyDomainname domain
cluster server-namemyServer1server-name
multicast-address239.255.0.1multicast-address identity1identity
enabledevs4jenabled cluster
... config
In Example 7–2
, the server is part of a domain called myDomain. For each server of the multi-server domain, the multicast-address elements
must contain the same value. The identity and server-name elements, however, must be different for each server in the multi-server domain.
Example 7–2 shows the config.xml file of a second server, called myServer2, in
the myDomain multi-server domain; note that this server’s identity is 2.
Example 7–2 myServer2 config.xml File
config
Note: When adding cluster element child elements, observe the
correct element order as Section 5.5, Order of cluster Element Child
Elements describes.
7-4 Oracle Complex Event Processing Administrators Guide
domain namemyDomainname
domain cluster
server-namemyServer2server-name multicast-address239.255.0.1multicast-address
identity2identity enabledevs4jenabled
cluster
... config
See Section 5.5, Order of cluster Element Child Elements
for a description of additional multi-server-related configuration elements and the required order of
child elements.
4.
Optionally, secure the messages that are shared between the servers in a domain by configuring encryption and digital signatures.
See Section 7.3.1, How to Secure the Messages Sent Between Servers in a
Multi-Server Domain Using Oracle CEP Native Clustering .
5.
To avoid a single point of failure, consider enabling
Oracle CEP Visualizer
on a small subset of n machines in the domain.
See How to Start Oracle CEP Visualizer in a Multi-Server Domain in the Oracle Complex Event Processing Visualizer Users Guide.
6.
Start all servers in your multi-server domain. See
Section 7.5, Starting and Stopping an Oracle CEP Server in a Multi-Server Domain
.
7.1.2 How to Create an Oracle CEP Multi-Server Domain With Custom Groups Using Oracle CEP Native Clustering
This procedure describes how to create a multi-server domain that uses custom groups to accommodate servers which are not completely homogenous.
If all the servers in your domain are completely homogeneous, you do not need to create custom groups. Instead, you can use the predefined groups: the singleton group
and domain group. See Section 7.1.1, How to Create an Oracle CEP Multi-Server
Domain With Default Groups Using Oracle CEP Native Clustering .
For more information about default and custom groups, see Section 5.2, Groups
.
Note: Enabling Oracle CEP Visualizer on a given Oracle CEP Server
may impact the performance of the server depending on the Oracle CEP Visualizer workload.
Note: In this section it is assumed that you have already created a
domain that contains a single server and that you want to add additional servers to the domain to make it a multi-server domain. See
Chapter 3, Administrating Oracle CEP Standalone-Server Domains for details on creating a domain.