openais.conf - openais executive configuration file
/etc/ais/openais.conf
The
openais.conf instructs the openais executive about various
parameters needed to control the openais executive. The
configuration file consists of bracketed top level
directives. The possible directive choices are totem { }
, logging { } , event { } , and amf { }.
These directives are described below.
totem { }
This top level directive contains configuration options for the totem protocol.
logging { }
This top level directive contains configuration options for logging.
event { }
This top level directive contains configuration options for the event service.
amf { }
This top level directive contains configuration options for the AMF service.
Within the totem directive, an interface directive is required. There is also one configuration option which is required:
Within the
interface sub-directive of totem there are four
parameters which are required:
ringnumber
This specifies the ring number for the interface. When using the redundant ring protocol, each interface should specify separate ring numbers to uniquely identify to the membership protocol which interface to use for which redundant ring.
bindnetaddr
This specifies the address which the openais executive should bind. This address should always end in zero. If the totem traffic should be routed over 192.168.5.92, set bindnetaddr to 192.168.5.0.
This may also be an IPV6 address, in which case IPV6 networking will be used. In this case, the full address must be specified and there is no automatic selection of the network interface within a specific subnet as with IPv4.
If IPv6 networking is used, the nodeid field must be specified.
mcastaddr
This is the multicast address used by openais executive. The default should work for most networks, but the network administrator should be queried about a multicast address to use. Avoid 224.x.x.x because this is a "config" multicast address.
This may also be an IPV6 multicast address, in which case IPV6 networking will be used. If IPv6 networking is used, the nodeid field must be specified.
mcastport
This specifies the UDP port number. It is possible to use the same multicast address on a network with the openais services configured for different UDP ports.
Within the
totem directive, there are seven configuration
options of which one is required, five are optional, and one
is required when IPV6 is configured in the interface
subdirective. The required directive controls the version of
the totem configuration. The optional option unless using
IPV6 directive controls identification of the processor. The
optional options control secrecy and authentication, the
redundant ring mode of operation, maximum network MTU, and
number of sending threads, and the nodeid field.
version
This specifies the version of the configuration file. Currently the only valid version for this directive is 2.
|
nodeid |
This configuration option is optional when using IPv4 and required when using IPv6. This is a 32 bit value specifying the node identifier delivered to the cluster membership service. If this is not specified with IPv4, the node id will be determined from the 32 bit IP address the system to which the system is bound with ring identifier of 0. The node identifier value of zero is reserved and should not be used. |
secauth
This specifies that HMAC/SHA1 authentication should be used to authenticate all messages. It further specifies that all data should be encrypted with the sober128 encryption algorithm to protect data from eavesdropping.
Enabling this option adds a 36 byte header to every message sent by totem which reduces total throughput. Encryption and authentication consume 75% of CPU cycles in aisexec as measured with gprof when enabled.
For 100mbit networks with 1500 MTU frame transmissions: A throughput of 9mb/sec is possible with 100% cpu utilization when this option is enabled on 3ghz cpus. A throughput of 10mb/sec is possible wth 20% cpu utilization when this optin is disabled on 3ghz cpus.
For gig-e networks with large frame transmissions: A throughput of 20mb/sec is possible when this option is enabled on 3ghz cpus. A throughput of 60mb/sec is possible when this option is disabled on 3ghz cpus.
The default is on.
rrp_mode
This specifies the mode of redundant ring, which may be none, active, or passive. Active replication offers slightly lower latency from transmit to delivery in faulty network environments but with less performance. Passive replication may nearly double the speed of the totem protocol if the protocol doesn’t become cpu bound. The final option is none, in which case only one network interface will be used to operate the totem protocol.
If only one interface directive is specified, none is automatically chosen. If multiple interface directives are specified, only active or passive may be chosen.
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netmtu |
This specifies the network maximum transmit unit. To set this value beyond 1500, the regular frame MTU, requires ethernet devices that support large, or also called jumbo, frames. If any device in the network doesn’t support large frames, the protocol will not operate properly. The hosts must also have their mtu size set from 1500 to whatever frame size is specified here. |
Please note while some NICs or switches claim large frame support, they support 9000 MTU as the maximum frame size including the IP header. Setting the netmtu and host MTUs to 9000 will cause totem to use the full 9000 bytes of the frame. Then Linux will add a 18 byte header moving the full frame size to 9018. As a result some hardware will not operate properly with this size of data. A netmtu of 8982 seems to work for the few large frame devices that have be