From 74aa0bc6779af38018a03fd2cf4419fe85917904 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 07:31:45 +0200 Subject: Adding upstream version 2.9.4. Signed-off-by: Daniel Baumann --- src/man/zh_CN/include/failover.xml | 120 +++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 src/man/zh_CN/include/failover.xml (limited to 'src/man/zh_CN/include/failover.xml') diff --git a/src/man/zh_CN/include/failover.xml b/src/man/zh_CN/include/failover.xml new file mode 100644 index 0000000..15d4fae --- /dev/null +++ b/src/man/zh_CN/include/failover.xml @@ -0,0 +1,120 @@ + + FAILOVER + + The failover feature allows back ends to automatically switch to a different +server if the current server fails. + + + Failover Syntax + + The list of servers is given as a comma-separated list; any number of spaces +is allowed around the comma. The servers are listed in order of +preference. The list can contain any number of servers. + + + For each failover-enabled config option, two variants exist: +primary and backup. The idea is +that servers in the primary list are preferred and backup servers are only +searched if no primary servers can be reached. If a backup server is +selected, a timeout of 31 seconds is set. After this timeout SSSD will +periodically try to reconnect to one of the primary servers. If it succeeds, +it will replace the current active (backup) server. + + + + The Failover Mechanism + + The failover mechanism distinguishes between a machine and a service. The +back end first tries to resolve the hostname of a given machine; if this +resolution attempt fails, the machine is considered offline. No further +attempts are made to connect to this machine for any other service. If the +resolution attempt succeeds, the back end tries to connect to a service on +this machine. If the service connection attempt fails, then only this +particular service is considered offline and the back end automatically +switches over to the next service. The machine is still considered online +and might still be tried for another service. + + + Further connection attempts are made to machines or services marked as +offline after a specified period of time; this is currently hard coded to 30 +seconds. + + + If there are no more machines to try, the back end as a whole switches to +offline mode, and then attempts to reconnect every 30 seconds. + + + + Failover time outs and tuning + + Resolving a server to connect to can be as simple as running a single DNS +query or can involve several steps, such as finding the correct site or +trying out multiple host names in case some of the configured servers are +not reachable. The more complex scenarios can take some time and SSSD needs +to balance between providing enough time to finish the resolution process +but on the other hand, not trying for too long before falling back to +offline mode. If the SSSD debug logs show that the server resolution is +timing out before a live server is contacted, you can consider changing the +time outs. + + + This section lists the available tunables. Please refer to their description +in the +sssd.conf5 +, manual page. + + + dns_resolver_server_timeout + + + + Time in milliseconds that sets how long would SSSD talk to a single DNS +server before trying next one. + + + Default: 1000 + + + + + + dns_resolver_op_timeout + + + + Time in seconds to tell how long would SSSD try to resolve single DNS query +(e.g. resolution of a hostname or an SRV record) before trying the next +hostname or discovery domain. + + + 默认： 3 + + + + + + dns_resolver_timeout + + + + How long would SSSD try to resolve a failover service. This service +resolution internally might include several steps, such as resolving DNS SRV +queries or locating the site. + + + Default: 6 + + + + + + + For LDAP-based providers, the resolve operation is performed as part of an +LDAP connection operation. Therefore, also the +ldap_opt_timeout timeout should be set to a larger value than +dns_resolver_timeout which in turn should be set to a larger +value than dns_resolver_op_timeout which should be larger +than dns_resolver_server_timeout. + + + -- cgit v1.2.3