TCP connections effect in case of waas failure

i need to know the effect of waas failure on the existing tcp connection.

Cisco WAAS utilizes standards-based TCP optimizations to remove TCP as a barrier to application performance over the WAN. By initiating a TCP Proxy after autodiscovery, communicating nodes experience LAN-like TCP behavior through local acknowledgement and TCP handling. As such, when the network goes down the TCP proxy has the ability to mask the disconnect for a short time, but after that all TCP connection will reset and clients will try to re-establish a connection.
For CIFS
-During transient disconnects (up to 95 seconds), the WAAS Edge maintains data in its buffers and retries the transmission to the WAAS Core upon network re-connect.
- When the WAAS Edge switches to "disconnected mode", its services change to "no service" and the buffered data is lost. Further file operations will fail and the Client will be alerted that the server is disconnected. Open documents can be "saved as" on another drive
-If the accessed file server was configured for "Disconnected Mode" CIFS clients will be able to continue to browse the cache directory and read fully cached files on an WAAS Edge
In addition with Windows on WAAS providing local window services (dns, authentication) user can access local file shares on WAVE

Similar Messages

WAAS - TCP Connection High-Water Mark

Is there a way to tell the historical statistic for maximum number of TCP connections in a WAE? We are in the middle of a deployment and I am wondering how well we sized our HQ cluster.

Through CM dashboard -> manage devices and go to edge or core device, you will be able to see the connections for each device.
The other option, is to check and see if you are seeing a lot of bypass traffic.
Once WAAS reaches max, traffic will be bypassed until max sessions drops

SbRIO-9612 unable to close a TCP connection without causing TCP failure

Hello,
I'm working on a multi-server (sbRIO-9612's), multi-client (Windows PCs) application which uses the STM 2.0 libraries and LV2009 SP1. The server listens on a UDP port for the client to send a message - once sent, the server opens the TCP connection to the client and all is well . . .
. . . until I added a "hearbeat" message to monitor for down connections. Once the TCP connection has been extablished, the client PC sends a TCP message (a request for the number of clients connected) to the server sbRIO-9612 every 5 seconds - both the client and server are coded to close the connection if a message is not received within 10 seconds. The client-side app works fine - if the TCP message is not returned in 10 seconds, the connection is closed and a new UDP message is sent to re-establish it.
The server-side is the problem - if no message is received in 10 seconds, the TCP connection is closed o.k. (no errors), but the server will no longer allow new TCP connections to be established unless it's rebooted. It seems to work fine if I leave the non-communicating TCP connections open on the server-side, but I can see this leading to problems after several clients have disconnected without notifying the server properly.
Interestingly, if the client closes the TCP connection properly (via TCP Close in LV), the server detects it fine and there is no problem.
I'm allowing the operating system on both sides to select the TCP port to use.
Any help is greatly appriciated - thank you!
Al

Hi Al,
Thanks for the update -- I'm glad that you were able to find that the issue wasn't actually with the TCP VIs, and moreover that LabVIEW 2010 SP1 seems to have resolved the issue. I would still recommend combing through the code on the RT end to ensure that the LabVIEW 2010 SP1 upgrade really did 'fix' the underlying issue. It's somewhat strange that a version upgrade resolved TCP communication issues that you were having. I just want to be sure that the solution is a truly stable one.
Sanjay C.
Embedded Software Product Manager| National Instruments

WAAS Optimized TCP Connections

Hi all,
Is there any cli command that gives us an overview of the Total Optimized TCP Connections in the box for that moment ?
Best Regards,
Bruno PetrÃ³nio

Bruno,
Show stat tfo
Will give you the basics on the connections going through the box.
Show stat accelerator
Will give you details on connections going through the AOs.
There are sub commands for both of those CLIs.
Hope that helps,
Dan

WAAS/WAVE snmp monitoring of TCP connection count

hi everyone,
i'm wondering if it's possible to query the amount of TCP connections via snmp, that are handled by a wae.
it's an important characteristic value to check if optimization is working properly.
looked over the several MIB documented in the latest config guide, but unfortunately got no clue...
can anyone help?
thanks in advance!

This statistics is currently not instrumented through SNMP. You can, however, access this statistics through the following methods:
CLI
XML API
Transaction Logs
Regards,
Zach

How to prevent a TCP connection being closed when the VI that opened it finishes.

Hello everyone.
I am developing an application based around servers and clients communicating over TCP in LabVIEW 2012.
When the server/client opens a TCP connection ,it launches an asynchronosly running "connection handler", to which it passes the connection reference which then takes over all the communcation. This all works fine.
However - I have a situation where a client's connection handler can be informed of another "new" server. I would like it to open the connection (to see if it is still valid) and then pass this connection reference back to the client's main code to spawn a new connection handler. This prevents me locking up the Client's main code with a long-ish timeout if the "new" server is not actually accepting connections.
The issue is that if the connection handler that opened up the connection to the "new" server is stopped, then it appears to destroy the reference that it opened. This means that the other connection handler that was merrily communcating with the "new" server has its TCP communciations closed (I get an Error code 1 on a write).
I have created an example to demonstrate the issue which should be used as follows:
1. Run server.vi - it will listen for a connection on the port specifed on its BD.
2. Run CH Launcher.vi - it will open a connection to the server and pass the TCP reference to an instance of Connection Handler.vi which it launches.
3. The Connection Handler should send data to the Server
4. Stop the CH Launcher.vi
5. The Connection Handler.vi will error.
Any suggestions would be much appreciated.
Cheers
John
Solved!
Go to Solution.
Attachments:
TCP Test.zip ‏35 KB

John_Neutron escreveu:
In my case I have changes the part of the code that opens the TCP connection to a VI that has the same lifetime as the main VI so that any connections that have been opened will only be closed automatically when the main VI stops.
And what are the effects? You are still facing the same problem or closing the connection only when the whole applicaton stops solved your problem?
Regards
Mondoni

Windows XP doesnt detect broken TCP connection

Hi Guys,
I have a client and a server. When they are both on a linux or both on a Windows machines there is no problem.
When the server is on linux and the client is on Windows XP, when the server goes down, the client does not recieve a SocketException.Connection Reset like it should.
It works fine otherwise, does anyone know why Windows cant see the TCP connection breaking if the server is on linux?

Java's platform independence cannot shield you from all variations in the implementation of the TCP/IP stack in the underlying operating system.
If you need to do special tricks for different operating systems chances are you are doing something in a non-optimal way. For the vast majority of programmers TCP/IP "Just Works". You open your sockets, do I/O on them, eventually close them.
If you write into a socket whose peer has done receive shutdown you eventually get an IOException (I'll guesstimate within one or three minutes absolute worst case). If you don't get the IOException then likely your program has a bug, such as ignoring exceptions. Far lesser likelihood is OS bug.
When you say "server goes down" do you mean the OS goes down (as in unplug the network connector), or the OS is shut down with a "shutdown" command, or the program is closed? TCP/IP will behave differently if the remote OS is forcefully brought down vs. the program exits and OS remains running. A "shutdown" command may exhibit either behaviour, depending on OS implementation and random timing effects.

Anyone else having an issue with TCP connections using iCloud for Windows?

Hi,
Before I asked this question, I did wait to see if any related questions came up, but none did, so I submit it now.
On my admittedly older laptop running Windows 7 64b Home, I've run into difficulties with the iCloud for Windows app to the extent that I had to uninstall it.
It would that, as my laptop was running, in the background, iCloudServices.exe would endlessly iterate TCP connections, which, while not actively sending or receiving any data, after some hours would number over 100 instances, taking up resources, and grinding my laptop's WiFi connection to a grindingly slow pace. I ended up, within the app, turning off everything, iCloud Drive and Photos, (I never used bookmarks), but still this would continue to occur.
I contacted Apple Support, explaining what was going on, and they stated they only dealt with IOS and gave me a Microsoft Support number. When I called Microsoft support, I came more and more to the realization that the issue was specifically with the iCloud for Windows app, as that was the only software that was endlessly creating and not closing TCP connections as it was. How was Microsoft supposed to solve an issue with Apple code?
So I called Apple back, whereupon they insisted it was a Microsoft issue. I explained other cloud services installed on the same computer were not having the same issue, it was unique to ICloudServices.exe. They stated they only dealt with IOS. I stated I purchased an iPad Air less than 7 months ago, and was trying to run iCloud in support of that. They again stated they only dealt with IOS, and suggested I again try Microsoft. I asked them if it was reasonable to expect Microsoft to solve issues with Apple code? They said regardless, there was zero support offered for anything having to do with Windows, and all I could do was uninstall the app, which I did, though that did not feel very satisfactory to me. My thinking is, if Apple writes a Windows app in support of their hardware, they should offer support for it.
Anyway, I was just wondering, is this an issue unique to me? or have others experienced a similar issue? I found this issue by opening the Windows Resource Monitor, looking under the Networking tab, and scrolling through the TCP Connections section to find 100+ concurrent iCloudServices.exe instances listed, whereas even Chrome, with multiple tabs and extensions, topped out at around 20.
My one month old Desktop, DYI, sports a solid Asus 1150 MoBo, i7-4790k cpu, 16GB Ram, and an EVGA GTX 970 video card. I list some specs only to illustrate this computer has no hardware issues in comparison to my long in tooth laptop. On this desktop, running Win 8.1 Pro 64b, at least as many, identifiably Apple, background service TCP connections are created even compared to Chrome, regardless of many tabs being open, many extensions, and even some related apps. Adobe does not even come close, though I run the full CC subscription. On this new computer, running Windows 8.1 Pro 64b, there are currently over 50 TCP connections and loopbacks that do not identify themselves, with just a - for the Image, and PID. With the experience on my laptop, I wonder how many of these are generated by Apple software, if not specifically iCloud software?
The frustrating aspect of these connections is they seem in no way active, While the Chrome and Adobe connections can be seen to be transferring data, as long as I am not running iTunes, or so have my iPad actually plugged in, it seems 99% of the time these iCloudServices.exe connections are just taking up ports, neither sending nor receiving any data discernable to me under the Processes with Network Activity, or Network Activity lists, both displayed in the same window as the TCP Connections in the Windows Resource Monitor.
Though I am fairly ignorant as regards coding, it seems as if there is no call to close a connection, very specifically, iCloudServices.exe, when it is no longer needed, and the next time a connection is needed, a new one is opened, rather than accessing the one previously opened. The only other reason I could imagine this might be occurring is if my Norton Internet Security software might mask and/or block the port after a certain time of inactivity.
Anyone out there have any ideas or advice about this? Thanks in advance.

Thanks jared,
I'm still dealing with this issue through Apple. Some time after I posted this, I contacted Apple again. They did start a case up for me, as I was experiencing the same behavior on two different machines, with two different versions of Windows.
So far it remains unsolved. I've logged iClouds for Windows on my desktop, which is brand new, then logged for awhile after completely uninstalling Norton Security Suite, depending on the Microsoft security for some time, and finally logged after I uninstalled iCloud for Windows, restarted, installed a clean download, and connected using a completely different test account, which Apple set up for me. None of this made any difference. Looking at the logs, it seems every 10 minutes, iCloudServices.exe creates a new TCP connection to confirm I'm using less than 5GB on iCloud, (which I am by a good margin, using less than 2GB), it seems this connection is not closed, and when the next iteration rolls around 10 minutes later, a new TCP connection is created. I come very close to having 6 TCP connections created per hour, until I restart my computer. This works out to... 6 x 24 = 144/day.
Perhaps the article you posted will shed some further light on this. I'm thinking seeing the state of the connection through netstats, at the least, could help.
For the last week, I've been putting a hold on further logging, as Apple wants me to create a new user account on one of my computers, install iCloud for Windows there, and log it running in the other account. This however basically means I cannot use my computer for a fair number of hours, and I've been busy enough with work the past week that I haven't the time or energy to afford to set this up and run it. I've had need of my computers too much for the past week.

TCP connection error when sending MODBUS commands to WAGO 750-881 controller after 113655 bytes of data have been sent

Hi all,
I am new to the world of labview and am attempting to build a VI which sends commands to a 750-881 WAGO controller at periodic intervals of 10ms.
To set each of the DO's of the WAGO at once I therefore attempt to send the Modbus fc15 command every 10ms using the standard Labview TCP write module.
When I run the VI it works for about a minute before I recieve an Error 56 message telling me the TCP connection has timed out. Thinking this strange, I decided to record the number of bytes sent via the TCP connection whilst running the program. In doing so I noticed that the connection broke after exactly 113655 Bytes of data had been sent each time.
Thinking that I may have been sending too many messages I increased the While-loop delay from 10ms to 20, 100 and 200 ms but the error remained. I also tried playing with the TCP connection timeout and the TCP write timeout but neither of these had any effect on the problem.
I cannot see why this error is occuring, as the program works perfectly up untill the 113655 Bytes mark.
I have attached a screenshot of the basic VI (simply showing a MODBUS command being sent every second) and of a more advanced VI (where I am able to control each DO of the WAGO manually by setting a frequency at which the DO should switch between ON and OFF).
If anybody has any ideas on where the problems lie, or what I could do to further debug the program this would be greatly appreciated.
Solved!
Go to Solution.
Attachments:
Basic_VI.png ‏84 KB
Expanded_VI.png ‏89 KB

AvdLinden wrote:
Hi ThiCop,
Yes the error occurs after exactly 113655 bytes every time. The timeout control I would like to use is 10ms, however even increasing this to 1s or 10s does not remove the error, which leads me to believe that this is not the issue (furthermore, not adding any delay to the while loop, thus letting it run at maximum speed, has shown that the TCP connection is able to send all 113655 bytes in under 3 seconds again pointing towards the timeout control not being the issue here).
I attempted Marco's suggestion but an having difficulty translating the string returned into a readable string, (rightnow the response given is " -# + ").
As to your second suggestion, I implemented something similar where I created a sub VI to build a TCP connection, send a message and then close the connection. I now build each message and then send the string to this subVI which successfully sends the command to my application. Whilst not being the most elegant method of solving the issue, it has resolved the timeout problem meaning I am able to send as many commands as I want. So in that sense the problem has been solved.
If you still have tips on how to correctly read the TCP read output, I would however like to see if I could not get my first program to work as it is slightly more robust in terms of timing.
Modbus TCP RTU is a binary protocol, as you show in your Basic VI, where you format the data stream using byte values. So you have to interprete the returned answer accordingly with the Modbus RTU spec in hand. Now what is most likely happening is that the connection gets hung after a while since you do NOT read the data the device sends as response to your commands. The TCP/IP stack buffers those bytes and at some point the internal buffers overflow and the connection is blocked by the stack. So adding the TCP Read at strategic places (usually after each write) is the proper solution for this. Is there any reason that you didn't use the NI provided Modbus TCP library?
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

No connect due to DbSl Load Lib Failure - During upgrade

Hi,
I am in the middle of performing PREPARE on a ECC 5.0 system to upgrade to ECC 6.0. During the phase PR_DBPAR the following error is coming:
SAPup> Starting subprocess 15413368 at 20080525190758
ENV <0x1105f2e90>: ORACLE_PSRV=DR5
ENV <0x1105f2ed0>: PATH=/oracle/DR5/102_64/bin:.:/home/dr5adm:/usr/sap/DR5/SYS/e
xe/runU:/usr/sap/DR5/SYS/exe/run:/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/
sbin:/usr/java14_64/jre/bin:/usr/java14_64/bin
ENV <0x1105f3070>: NLS_LANG=AMERICAN_AMERICA.UTF8
ENV <0x1105f30d0>: ORACLE_BASE=/oracle
ENV <0x1105f3290>: dbs_ora_tnsname=DR5
ENV <0x1105f32d0>: ORACLE_SID=DR5
ENV <0x1105f34b0>: DIR_LIBRARY=/usr/sap/put/exe
ENV <0x1105f3670>: dbs_ora_schema=SAPDR2
ENV <0x1105f3830>: ORA_NLS33=/oracle/client/9208/ocommon/nls/admin/data
ENV <0x1105f3990>: ORACLE_HOME=/oracle/DR5/102_64
ENV <0x1105f3a70>: dbms_type=ORA
ENV <0x1105f3c30>: LIBPATH=/usr/sap/put/exe:/usr/sap/DR5/SYS/exe/run
ENV <0x1105f3d50>: auth_shadow_upgrade=0
EXECUTING /usr/sap/put/exe/tp (tp) pf=/usr/sap/put/bin/DEFAULT.TPP execdbscript
DR5 -x SQLDBSCRIPT.TQL
This is /usr/sap/put/exe/tp version 372.04.08 (release 700, unicode enabled)
ERROR: No connect due to DbSl Load Lib Failure
ERROR: The values set for DIR_LIBRARY ('/usr/sap/put/exe') or dbms_type ('ORA')
ERROR: Connect to DR5 failed (20080525190759).
Warning: Parameter INTERRUPT is no longer used.
Warning: Parameter DAYLIGHT_SHUTDOWN is no longer used.
Warning: Parameter WITH_TACOB is no longer used.
Warning: Parameter IMPDP_BY_EVENT is no longer used.
Warning: Parameter INTERRUPT is no longer used.
Warning: Parameter DAYLIGHT_SHUTDOWN is no longer used.
Warning: Parameter WITH_TACOB is no longer used.
Warning: Parameter IMPDP_BY_EVENT is no longer used.
Warning: Parameter DBCONFPATH is no longer used.
Warning: Parameter STARTDB is no longer used.
Warning: Parameter STOPDB is no longer used.
TRACE-INFO: 1: [dev trc     ,00000] Sun May 25 19:07:59 2008
                   4777 0.004777
TRACE-INFO: 2: [dlux.c      ,00000] *** ERROR => DlLoadLib: dlopen()=
0509-130 Symbol resolution failed for /usr/sap/put/exe/dboraslib.o because:
TRACE-INFO: 3:                          0509-136   Symbol OCIClientVersion (numb
er 130) is not exported from
TRACE-INFO: 4:                                     dependent module /usr/sap/DR5
/SYS/exe/run/libclntsh.a[shr.o].
TRACE-INFO: 5:                          0509-022 Cannot load module /usr/sap/put
/exe/dboraslib.o.
TRACE-INFO: 6:                          0509-026 System error: Cannot run a file
that does not have a valid format.
TRACE-INFO: 7:                          0509-192 Examine .loader section symbols
with the             58 0.004835
TRACE-INFO: 8:                                   'dump -Tv' command. -> DLENOACC
ESS (8,Exec format error)
tp returncode summary:
TOOLS: Highest return code of single steps was: 0
ERRORS: Highest tp internal error was: 0249
tp finished with return code: 249
meaning:
connect failed due to DbSL load lib failure
Process with ID 15413368 terminated with status 249
We are having oracle 10g on AIX 5.3.
I tried options like setting LIBPATH with /oracle/client/10x_64/instantclient (instead of the default /oracle/client/9208/lib) along with /usr/sap/DR5/SYS/exe/run and having LIBPATH only with /usr/sap/DR5/SYS/exe/run and having env variable DBS_LIBPATH_EXT=/oracle/client/10x_64/instantclient (as per note 836517)
but if i try to restart PREPARE again, it is picking up the changes happening in LIBPATH (but same error) and also it not picking up DBS_LIBPATH_EXT env variable at all (may be if i try to make it permanent using .sh file it will pick up but i dont want that)
With all the above said, anyone has any perfect idea to have this issue fixed and continue the prepare process ?
Thanks,
Murali.

Hi Markus,
Thanks for your reply. The issue is as follows:
If i keep the current default value of the env variable LIBPATH which is
LIBPATH=/usr/lib:/lib:/usr/sap/DR5/SYS/exe/run:/usr/sap/DR5/SYS/exe/runU:/oracle
/client/9208/lib
and being in /usr/sap/SID/SYS/exe/run (which is 6.40 kernel ECC 5.0) if i execute
ldd dboraslib.o the following is the output:
dboraslib.o needs:
         /usr/sap/DR5/SYS/exe/run/libsapu16.so
         /usr/sap/DR5/SYS/exe/run/libclntsh.a(shr.o)
         /oracle/client/9208/lib/libwtc9.so
         /usr/lib/libc.a(shr_64.o)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         /usr/lib/libdl.a(shr_64.o)
         /usr/lib/libodm.a(shr_64.o)
         /usr/lib/libc.a(aio_64.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
being in /usr/sap/put/exe (which is in the middle of PREPARE step for ECC 6.0 upgrade, so it put kernel 7.0 files), the following is the output:
dboraslib.o needs:
         /usr/lib/libc.a(shr_64.o)
         /usr/sap/DR5/SYS/exe/run/libclntsh.a(shr.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         /usr/lib/libdl.a(shr_64.o)
         /usr/lib/libodm.a(shr_64.o)
         /usr/lib/libc.a(aio_64.o)
But if i change the environment variable for LIBPATH as follows:
LIBPATH=/oracle/client/10x_64/instantclient:/usr/lib:/lib:/usr/sap/DR5/SYS/exe/run:
/usr/sap/DR5/SYS/exe/runU (since we have already installed oracle 10g which is up and running and so we have already installed instant client also during that process)
the following is what the output for both the path as mentioned earlier:
#[/usr/sap/put/exe]
#dr5adm@sapdr5-3d[DR5]> ldd dboraslib.o
dboraslib.o needs:
         /usr/lib/libc.a(shr_64.o)
         /oracle/client/10x_64/instantclient/libclntsh.a(shr.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         /usr/lib/libdl.a(shr_64.o)
         /usr/lib/libodm.a(shr_64.o)
         /usr/lib/libperfstat.a(shr_64.o)
         /usr/lib/libcfg.a(shr_64.o)
         /usr/lib/liblvm.a(shr_64.o)
#[/usr/sap/DR5/SYS/exe/run]
#dr5adm@sapdr5-3d[DR5]> ldd dboraslib.o
dboraslib.o needs:
         /usr/sap/DR5/SYS/exe/run/libsapu16.so
         /oracle/client/10x_64/instantclient/libclntsh.a(shr.o)
         /oracle/client/92x_64/lib/libwtc9.so
         /usr/lib/libc.a(shr_64.o)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         /usr/lib/libdl.a(shr_64.o)
         /usr/lib/libodm.a(shr_64.o)
         /usr/lib/libperfstat.a(shr_64.o)
         /usr/lib/libc.a(aio_64.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
         /usr/lib/libcfg.a(shr_64.o)
         /usr/lib/liblvm.a(shr_64.o)
DIR_LIBRARY on both the cases and by default also is /usr/sap/SID/SYS/exe/run (pointing to running 6.40 kernel)
But if i try the PREPARE with or without this changes, the issue what i reported is what happening. Let me know your ideas on this.
Thanks,
Murali.

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider,

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider,
error: 40 - Could not open a connection to SQL Server)

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named
Pipes Provider, error: 40 - Could not open a connection to SQL Server)
Hello,
Make sure your SQL Server service is started.
Make sure TCP\IP and names pipes protocol is enabled
Make sure you have made an exception in firewall for SQL Server connection
Make sure SQL Server browser service is enabled
Make sure you connect with correct name hostname\instance name for named instance,MSSQLSERVER for default instance and Hotname\SQLEXPRESS for express edition.
Please make sure you use port no when connecting to SQL server listeing on different port (hostname\instance ,portno)
http://blogs.msdn.com/sql_protocols/archive/2006/09/30/SQL-Server-2005-Remote-Connectivity-Issue-TroubleShooting.aspx
Hope this helps
Please mark this reply as the answer or vote as helpful, as appropriate, to make it useful for other readers

RMI TCP Connection in a log file - connection count in brackets?

Hello,
I have a server whcih logs RMI connections to a file. For example, I can find these kind of log-lines in the file:
2009-10-19 07:43:33,809 INFO [RMI TCP Connection(2559)-109.84.36.165] de.test.foo..FooService This is the log messageI wonder what the number in brackets means: (2559)
Does it represent the number of currently open connections (this would be very bad in my case), or is it just a simple counter to distinguish between different RMI connections in the log file?
Thanks a lot for your help!

Hello,
thanks for your answer, good to hear that it is just a counter. I was not seriously thinking that it was a connection count - but you know, there are moments when I just have to ask to be sure ;)

I sometimes get Error 42 when opening a TCP connection - how can I fix this ?

In my Labview application I am opening a TCP connection in an identical way to the Data Client example. I am using a direct connection to external equipment using an ethernet crossover cable. The error occurs on at least 2 different PCs.
The error can occur regardless of whether anything is connected to the ethernet port of the PC.
The only way I have found to clear the error is to power down the PC and restart with a connection to the office LAN. Then I can swap back to the crossover cable and talk to the remote equipment once again, ...unitl the next time the error occurs.
I have LabView 6.0 running on Win98.
Any help greatly appreciated.

Jeremy,
Thanks for taking the time to answer
I already checked the link you suggested but I am connecting to my remote instrument with a 2m cross-over cable.
I Have looked into this a little further, it seems the sequence of events is as follows -
1. After some hours the connection gets lost.
2. TCP Read returns error 66 - Connection was closed by peer.
3. If I try to restart my program I get Error 42 at TCP open Connection.
4. Rebooting the PC doesn't clear the error 42 problem.
5. If I try to PING my instument I get "Host unreachable".
6. I have to "refresh" my network card by connecting to our LAN and either opening a file on another PC or simply sending a PING to another PC.
6. I can then reconnect my remote instrument via cross-over cable
and we're up and running for another few hours.
I get the same problem on two different PCs with different NICs and different OS (Win98 and WinME)
I am assuming that because a reboot has no effect that its not a memory allocation problem.
It seems like LabView stops talking to the NIC and then gets locked out some how.
Any other tips ?

Resolving a TCP connection "slowdown" problem

SuSE 9.3, stock kernel
Intel architecture
Jrockit-R26.4.0-jdk1.5.0_06-linux-ia32
I have a problem that appears to be localized in Jrockit (or
localized in the application, which is localized in Jrockit), where a
persistent and high-volume TCP connection slows down over the course
of about an hour--and eventually, effectively halts.
The TCP traffic is a stream of data, arriving at a near-constant rate
of about 16K bytes per second, with the receiving end (with the JVM
and app) strictly sending TCP ACKs in reply.
Restarting the sending process, or shutting down and restarting the
connection with the JVM / app, both restore the connection to full
speed until, over the course of perhaps an hour (sometimes more,
sometimes less) the same symptoms appear.
The symptoms in network packet traces are that when the connection is
first opened, the sender transmits packets at the full MTU of the
Ethernet segment. Gradually, the number of full-MTU sized packets
are replaced with packets much smaller packets, until most packets
range from 1 to 4 bytes with the occasional 3xx-4xx byte packet and
the odd offlier of a full-MTU packet size.
Supporting symptoms of interest:
1) The TCP window does not shrink
2) The CPU on the JVM/app side tops out at around 20%, even with
mySQL running on the machine
3) The interval between successive ACKs transmitted from the JVM/app
size generally narrows over the course of the connection
4) TCP send queue on the sender becomes saturated (pegged at 90+ K)
5) TCP receive queue on the JVM/app side is almost always 0, and when
it is not zero is bursts up to a low number (<50) and then almost
immediately returns to 0
6) The app does not appear to present any general symptoms of
slowness; the rate of writes to the database does not appear to slow.
The writes are threaded and multiplexed
[4] strongly implies that the slowness is caused by the JVM/app side,
since if the sender app was slowing down for some reason its TCP send
queue would not be saturated.
I can copiously document everything stated, and additionally provide
much additional detail.
Any guidance on how to suss out role Jrockit or the app are playing
in this little drama would be very deeply appreciated.

Asked around and it seems unlikely that this is a JVM issue. We have never heard of this behavior before, and the network layer in the JVM doesn't do anything with MTU iirc with the possible exception of manual changes to socket options. It seems more likely that this is caused by the IP stack, the NIC device driver or something in the network configuration. Try making some changes here and see what happens. For instance:
1) Run client and server on the same machine, communicating through loopback
2) Try another Linux distro (CentOS 4.3, for instance)
3) Try a different NIC and/or a different device driver
In your Java code, check that you are closing all Socket objects properly. Leaving them to be closed by a finalizer can delay closing sockets resulting in a native resource leak. I don't see how that would cause the issue you describe, but you never know...

Still looking for anwers to TCP Connection data

Can flash monitor TCP connection status? I need to read it
somehow and then send that info back to the server. Posted this a
number of weeks ago, but not a single nibble.
Anyone?

The server only uses port 80 in this case, and we are not
connecting to any other domains. He can't seem to get a policy file
to work, so the whole thing has now become my fault.
The deal is, using the .close(); method works fine, but his
PHP is pushing the file anyway. It took me a week to discover that
this issue isn't mine. But .. the php developer is convinced that I
haven't written the AS properly, or we wouldn't have this issue. I
simply state that the way I am using the .close() method works
fine, but his code is overriding it, which is out of my hands. But
I am trying to find a solution, and we are both thinking this
socket connection may be it, we just can't get it to work without
errors.
Funny, he pointed me to a site that he says does exactly what
he wants this to do, and it throws at least six errors before the
song finally plays. He has not acknowledge that minor deatil yet.
:)

TCP connections effect in case of waas failure

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