autofs-5.0.3 - update replicated server selection documentation From: Ian Kent Update the replicated server selection README documentation to reflect the selection rules now used. --- CHANGELOG | 1 + README.replicated-server | 53 ++++++++++++++++++++++------------------------ 2 files changed, 26 insertions(+), 28 deletions(-) diff --git a/CHANGELOG b/CHANGELOG index af3318a..be39e33 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -31,6 +31,7 @@ umount during expire. - make mount of multi-mounts wuth a root offset atomic. - add replicated server selection debug logging. +- update replicated server selection documentation. 14/01/2008 autofs-5.0.3 ----------------------- diff --git a/README.replicated-server b/README.replicated-server index 333dea3..1d771d3 100644 --- a/README.replicated-server +++ b/README.replicated-server @@ -3,48 +3,45 @@ Supported forms for mount paths are: Normal single-host (these are unchanged) host:/path/path +Single host entries are not probed for a server response. + Multiple replicated hosts, same path: host1,host2,hostn:/path/path -This will do an initial RPC call with a .1 second timeout to all hosts to -find best match. If this fails, it will try a 10 second timeout, if this -fails it takes the first host. - Multiple hosts, some with same path, some with another host1,host2:/blah host3:/some/other/path -Works as expected - Multiple replicated hosts, different (potentially) paths: host1:/path/pathA host2:/path/pathB -Same as above with RPC calls.. - Mutliple weighted, replicated hosts same path: - host1(5),host2(6),host3(1):/path/path -Will pick lowest weighted host that responds to RPC call. -RPC time is not counted, only whether the call got a reply -at all. Initially does a .1 second timeout, if all hosts -fail this, moves to 10 second timeout. If one of the hosts -is localhost, the automounter will choose that regardless of -its weight. (This has been done to remain compatible with -Sun's automounter) - Multiple weighted, replicated hosts different (potentially) paths: host1(3):/path/pathA host2(5):/path/pathB -Same as above with RPC calls/weighting. - -Anything else is questionable and unsupported, but these -variations will also work: - host1(3),host:/blah - -Unsupported and I don't know why you would use this, but will -work. Weighted host always gets precedence if it responds to RPC - -Anything else, I ain't making no promises. +For these formats a priority ordered list of hosts is created by using +the following selection rules. + +1) Highest priority in selection is proximity. + Proximity, in order of precedence is: + - PROXIMITY_LOCAL, host corresponds to a local interface. + - PROXIMITY_SUBNET, host is located in a subnet reachable + through a local interface. + - PROXIMITY_NETWORK, host is located in a network reachable + through a local interface. + - PROXIMITY_OTHER, host is on a network not directlty + reachable through a local interface. + +2) NFS version and protocol is selected by caclculating the largest + number of hosts supporting an NFS version and protocol that + have the closest proximity. These hosts are added to the list + in response time order. Hosts may have a corresponding weight + which essentially increases response time and so influences the + host order. + +3) Hosts at further proximity that support the selected NFS version + and protocol are also added to the list in response time order as + in 2 above. -Jason