vlserver: rx_SetRxDeadTime before ubik init

Currently, vlserver calls rx_SetRxDeadTime to set the default rx
deadtime to 50 seconds, but it does so after calling
ubik_ServerInitByInfo. ubik_ServerInitByInfo creates several rx
connections before it returns, and so these connections get the
default rx deadtime (12 seconds), instead of the 50 seconds vlserver
tries to set.

When ubik detects that a remote site is down, ubik recreates the rx
connections for that site, and this new connection gets the new
deadtime of 50 seconds.

This means that ubik behavior can have different timings in the
vlserver, depending on if any remote sites have ever been detected as
being 'down' or not. This can result in seemingly-inconsistent or
confusing behavior, since some sequences of operations that appear
identical can produce different results, depending on if the 12-second
timeout or the 50-second timeout is being used.

This behavior is not directly to blame for any problems, but it can be
very confusing, especially when trying to diagnose or reproduce bugs.
So to make things more consistent, just call rx_SetRxDeadTime earlier,
so all conns always get the 50-second timeout.

In order to do this, though, we must also ensure that rx_Init is
called before rx_SetRxDeadTime (otherwise, rx_Init will overwrite our
configured deadtime). So also call rx_Init earlier; rx_Init is
idempotent, so it's okay that it may be called again after or before
this.

Note that vlserver is currently the only ubik server that sets a
deadtime of 50 seconds, and it's not clear why. Another way to solve
this is to just remove the call to rx_SetRxDeadTime, to make vlserver
behave more similar to ptserver. But this commit takes a conservative
approach to result in a deadtime that is probably the most common in
current use. Since, most long-running vlservers will probably
eventually lose contact with remote sites at one time or another, and
so will eventually use a deadtime of 50 seconds.

Change-Id: I49430144d9a62eb8cad1509c1aeafc9fcc927f8e
Reviewed-on: https://gerrit.openafs.org/12285
Tested-by: Andrew Deason <adeason@dson.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>

diff --git a/src/vlserver/vlserver.c b/src/vlserver/vlserver.c
index 22b29f3..08ecab9 100644 (file)
--- a/src/vlserver/vlserver.c
+++ b/src/vlserver/vlserver.c
@@ -477,6 +477,13 @@ main(int argc, char **argv)
        }
     }
 
+    code = rx_Init(htons(AFSCONF_VLDBPORT));
+    if (code < 0) {
+        VLog(0, ("vlserver: Rx init failed: %d\n", code));
+        exit(1);
+    }
+    rx_SetRxDeadTime(50);
+
     ubik_nBuffers = 512;
     ubik_SetClientSecurityProcs(afsconf_ClientAuth, afsconf_UpToDate, tdir);
     ubik_SetServerSecurityProcs(afsconf_BuildServerSecurityObjects,
@@ -490,7 +497,6 @@ main(int argc, char **argv)
        VLog(0, ("vlserver: Ubik init failed: %s\n", afs_error_message(code)));
        exit(2);
     }
-    rx_SetRxDeadTime(50);
 
     memset(rd_HostAddress, 0, sizeof(rd_HostAddress));
     memset(wr_HostAddress, 0, sizeof(wr_HostAddress));