Advisors are agents within Load Balancer. Their purpose is to assess the health and loading of server machines. This list of advisors are already provided with Load Balancer, but you can also write a custom advisor to suit specific needs.
Advisor Name | Description |
---|---|
connect | The connect advisor does not exchange any protocol-specific data with the server. It simply measures the time it takes to open and close a TCP connection with the server. This advisor is useful for server applications which use TCP, but with a higher-level protocol for which an IBM-supplied or custom advisor is not available. |
Custom advisors | Dispatcher provides the ability for a customer to write a custom (customizable) advisor. This enables support for proprietary protocols (on top of TCP) for which IBM has not developed a specific advisor. For more information, see Creating a custom advisor. |
db2 | The DB2 advisor works in conjunction with the DB2 servers. Dispatcher has the built in capability of checking the health of DB2 servers without the need for customers to write their own custom advisors. The DB2 advisor communicates with the DB2 connection port only, not the Java connection port. |
dns | The DNS advisor opens a connection, sends a pointer query for DNS, waits for a response, closes the connection and returns the elapsed time as a load. |
ftp | The FTP advisor opens a connection, sends a SYST request, waits for a response, closes the connection, and returns the elapsed time as a load. |
http | The HTTP advisor opens a connection, sends a HEAD request by default, waits for a response connection, and returns the elapsed time as a load. See Getting service-specific advice with the advisor request or response optionfor more information on how to change the type of request sent by the HTTP advisor. |
https | The HTTPS advisor is a ″heavyweight″ advisor
for SSL connections. It performs a full SSL socket connection with
the server. The HTTPS advisor opens an SSL connection, sends an HTTPS
request, waits for a response, closes the connnection, and returns
the elapsed time as a load. (See also the SSL advisor, which is a
″lightweight″ advisor for SSL connections.) Note: The HTTPS advisor
has no dependency upon server key or certificate content, but they
must not be expired.
|
imap | The IMAP advisor opens a connection, waits for an initial message from the server, sends a quit command, closes the connection, and returns the elapsed time as a load. |
ldap | The LDAP advisor opens a connection, sends an anonymous BIND request, waits for a response, closes the connection, and returns the elapsed time as a load. |
ldapuri | ![]() The LDAP URI advisor
allows you better gauge LDAP availability by processing a complete
request to the LDAP server.
The advisor:
newfeat
|
nntp | The NNTP advisor opens a connection, waits for an initial message from the server, sends a quit command, closes the connection, and returns the elapsed time as a load. |
ping | The ping advisor does not open a TCP connection with the servers, but instead reports whether the server responds to a ping. While the ping advisor may be used on any port, it is also designed for configurations using the wildcard port, over which multiple protocol traffic may be flowing. It is also useful for configurations using non-TCP protocols with their servers. |
pop3 | The POP3 advisor opens a connection, waits for an initial message from the server, sends a quit command, closes the connection, and returns the elapsed time as a load. |
reach | The reach advisor pings its target machines. This advisor is also designed for the Dispatcher's high availability components to determine reachability of its reach targets. Its results flow to high availability component and do not appear in the manager report. Unlike the other advisors, the reach advisor starts automatically by the manager function of the Dispatcher component. |
sip | The SIP advisor opens a connection, sends an OPTIONS request, waits for a response, closes the connection, and returns the elapsed time as a load. The SIP advisor that is supported runs on TCP only and requires an application to be installed on a server that responds to an OPTIONS request. |
smtp | The SMTP advisor opens a connection, waits for an initial message from the server, sends a quit, closes the connection, and returns the elapsed time as a load. |
ssl | The SSL advisor is a ″lightweight″ advisor for
SSL connections. It does not establish a full SSL socket connection
with the server. The SSL advisor opens a connection, sends an SSL
CLIENT_HELLO request, waits for a response, closes the connection,
and returns the elapsed time as a load. (See also the HTTPS advisor,
which is a ″heavyweight″ advisor for SSL connections.) Note: Be aware
of the following:
|
ssl2http | The ssl2http advisor starts and advises on the servers listed under port 443, but the advisor will open a socket to the “mapport″ for HTTP requests. |
self | The self advisor collects load status information on back-end servers. You can use the self advisor when using Dispatcher in a two–tiered configuration, where the Dispatcher furnishes information from the self advisor to the top-tiered Load Balancer. The self advisor specifically measures the connections per second rate on back-end servers of the Dispatcher at the executor level. See **** MISSING FILE **** for more information. |
telnet | The Telnet advisor opens a connection, waits for an initial message from the server, closes the connection, and returns the elapsed time as a load. |
tls | Transport Layer Security (TLS) is the successor
to the SSL protocol. TLS 1.0 was the follow up to SSLv3. You might want to use the TLS advisor if you find that the SSL advisor is marking servers down, you know that the server is still up, and you see messages stating "No ciphers found." |
was | The WAS (WebSphere Application Server) advisor works in conjunction with the WebSphere Application servers. Customizable sample files for this advisor are provided in the installation directory. For more information, see Example: Implementing the WAS advisor. |
wlm | The WLM (Workload Manager) advisor is designed to work in conjunction with servers on OS/390 mainframes running the MVS™ Workload Manager (WLM) component. For more information, see The Workload Management Advisor. |