#19 Can't run 2 or more pvAccess servers on the same host when VPN also running on host

[Greg White]

[BUG 1st reported in email,
https://sourceforge.net/mailarchive/forum.php?thread_name=42139F80-63A7-46E9-BC9F-3CFEBE185549%40slac.stanford.edu&forum_name=epics-pvdata-devel]

[This BUG supersedes previous similar BUG 14, which was closed to be replaced by this one.
The difference is that in 14, no VPN need be running. Though that behaviour of simply
'cant connect to 2 servers on the same host if both running at the same time', seems no longer to be the case. Now that observable requires VPN also to be running, at least in the host configuration described].

Two probably related issues of pvaccess connection timeout, that go away
when VPN is not running.

OS = Mac OS 10.9 (Mavericks),
VPN = Cisco AnyConnect - with the patch for 10.9 [1]
Servers, and the client, are executing on my laptop.

The first is that if VPN is on, eget will only connect to one, not more than one,
pvaccess server.

The second is, if a pvaccess server itself has a JDBC connection, then if VPN
is running, eget can't contact even to that single server. Ie, the >1 of the first
observation goes to 0.

Note that, with VPN on, eget requests over CA (to a remote host) still work fine!
Haven't ried CA server also running on the laptop and VPN.

Details

eget to 2 identical pvaccess RPC servers

Servers differing only in their RPCServer.registerService(service_name,...)
Say I have 2 identical java implemented services, which should respond to
"alen" and "alenka" respectively.

$ eget -s alen ... or eget -s alenka

Event        VPN    Connect successful
------------ ---    ------------------    
             OFF    -
START alen   OFF
eget->alen   OFF    yes
START alenka OFF    
eget->alenka OFF    yes
eget->alen   OFF    yes
[ok, good]
TURN VPN on  ON
eget->alen   ON     yes
eget->alenka ON     no         <- uh oh
STOP alen    ON
eget->alenka ON     yes        <- so, when VPN turned on, it "blocked" alenka
START alen   ON
eget->alenka ON     yes           
eget->alen   ON     no
STOP alenka  ON
eget->alen   ON     yes (!)    <- You can have one, or the other, but not both.
START alenka ON
eget->alenka ON      no 
eget->alen   ON      yes
TURN VPN OFF 
eget->alen   OFF     yes      
eget->alenka OFF     yes       <- VPN OFF, all connections successful again.

Note, this isn't to do with the state transition of VPN, you can start both servers after
VPN is turned on. eget can't connect to both.

[Greg White]

• Description has changed:

Diff:

--- old
+++ new
@@ -1,5 +1,9 @@
 [BUG 1st reported in email,
 https://sourceforge.net/mailarchive/forum.php?thread_name=42139F80-63A7-46E9-BC9F-3CFEBE185549%40slac.stanford.edu&forum_name=epics-pvdata-devel]
+
+[This BUG supersedes previous similar BUG 14, which was closed to be replaced by this one.
+The difference is that in 14, no VPN need be running. Though that behaviour of simply
+'cant connect to 2 servers on the same host if both running at the same time', seems no longer to be the case. Now that observable requires VPN also to be running, at least in the host configuration described]. 

 Two probably related issues of pvaccess connection timeout, that go away
 when VPN is not running. 
@@ -26,33 +30,33 @@
 Say I have 2 identical java implemented services, which should respond to
 "alen" and "alenka" respectively.

-$ eget -s alen ... or eget -s alenka
-
-Event        VPN    Connect successful
------------- ---    ------------------    
-             OFF    -
-START alen   OFF
-eget->alen   OFF    yes
-START alenka OFF    
-eget->alenka OFF    yes
-eget->alen   OFF    yes
-[ok, good]
-TURN VPN on  ON
-eget->alen   ON     yes
-eget->alenka ON     no         <- uh oh
-STOP alen    ON
-eget->alenka ON     yes        <- so, when VPN turned on, it "blocked" alenka
-START alen   ON
-eget->alenka ON     yes           
-eget->alen   ON     no
-STOP alenka  ON
-eget->alen   ON     yes (!)    <- You can have one, or the other, but not both.
-START alenka ON
-eget->alenka ON      no 
-eget->alen   ON      yes
-TURN VPN OFF 
-eget->alen   OFF     yes      
-eget->alenka OFF     yes       <- VPN OFF, all connections successful again.
+    $ eget -s alen ... or eget -s alenka
+    
+    Event        VPN    Connect successful
+    ------------ ---    ------------------    
+                 OFF    -
+    START alen   OFF
+    eget->alen   OFF    yes
+    START alenka OFF    
+    eget->alenka OFF    yes
+    eget->alen   OFF    yes
+    [ok, good]
+    TURN VPN on  ON
+    eget->alen   ON     yes
+    eget->alenka ON     no         <- uh oh
+    STOP alen    ON
+    eget->alenka ON     yes        <- so, when VPN turned on, it "blocked" alenka
+    START alen   ON
+    eget->alenka ON     yes           
+    eget->alen   ON     no
+    STOP alenka  ON
+    eget->alen   ON     yes (!)    <- You can have one, or the other, but not both.
+    START alenka ON
+    eget->alenka ON      no 
+    eget->alen   ON      yes
+    TURN VPN OFF 
+    eget->alen   OFF     yes      
+    eget->alenka OFF     yes       <- VPN OFF, all connections successful again.

 Note, this isn't to do with the state transition of VPN, you can start both servers after
 VPN is turned on. eget can't connect to both.

• Group: -->