Singletons running on two servers at the same time

Hello,
          we faced one interesting situation with our application, running on clustered BEA Weblogic 9.2. We implemented some Singletons (ie. Singleton Service in a Weblogic cluster) and they are running fine. Most of the time.
          Common scenarios: cluster is started -> the singletons run on one server; the server is brought down -> the singletons are started on the second server.
          However, we had recently two situations where the Singletons started on both servers! Here they are:
          1) We use Database Migration Basis and we have a dedicated table for Weblogic to capture current state of the singletons. Due to the fact that database (Oracle RAC) was partially available one of the Managed Server could not get the lease and probably assumed that no singleton is running, therefore started the singletons locally.
          2) Network outage: we had several minutes where none of our servers could communicate between them (neither between SASU MS nor with the database). Consequence: each MS decided to start the singleton locally (after some time, which I assume is the waiting time). Once the network came back the servers could communicate again but the duplicate singletons are not deactivate, so they are running in parallel.
          Anyone experienced the same or similar issues? How to prevent the above? Is the Consensus Migration Basis a better choice? (I think yes for #1 but not for situation #2).
          Any helpful answer is appreciated.
          Thank you, best regards,
          Remus.

In general its not a good idea. Running PSConfig will try to establish a lock on the configuration database. Doing that from two servers at the same time may cause the update to fail.
Paul Stork SharePoint Server MVP
Principal Architect: Blue Chip Consulting Group
Blog: http://dontpapanic.com/blog
Twitter: Follow @pstork
Please remember to mark your question as "answered" if this solves your problem.

Similar Messages

Running PSConfig on multiple servers at the same time

Hi - we are updating an 8 server farm with a CU and in order to reduce downtime I am wondering whether it is supported/risky to run PSConfig on multiple SharePoint servers at the same time
I plan to run the first one by itself - then after that set 7 off at the same time
In the past I have always run them serially just to be cautious but there is pressure to reduce downtime so I want to know if there is any risk in running them simultaneously
Thanks!
J

In general its not a good idea. Running PSConfig will try to establish a lock on the configuration database. Doing that from two servers at the same time may cause the update to fail.
Paul Stork SharePoint Server MVP
Principal Architect: Blue Chip Consulting Group
Blog: http://dontpapanic.com/blog
Twitter: Follow @pstork
Please remember to mark your question as "answered" if this solves your problem.

Can i run two widgets at the same time on the same page?

Can i run two widgets at the same time on the same page?
Hi
I have created and published 4 free ibooks and i would to run two widgets
- a countdown clock
- a review test
at the same time on the page. Can i do that?
Thanks in advance
Haris

thanks for your answer. Yes indeed HTML widgets run only full screen (snif snif). I consider this as a "distinguishing treatment".
One solution i read !!!!! was to create through keynote a countdown clock, to export to quicktime move and to imported at iBA predefined widgets. of course this is not the solution i need.
So, in order to have at the same widget and run together a count down clock and a preview test (20 questions) i must
1)"hack" the preview widget and insert a countdown clock
2) create a preview test using iAD.....
thanks again
haris

Run two VIs at the same time

Hello!
I want to know how i can run two VIs at the same time.
I mean that i want to run a second VI ( N.2) while another VI (N.1) is in
execution without suspend it (N.1)
If anyone has suggestions, please help me!
Thank you very much.
roby.

If you say "run a vi", I assume that you have the VI open in LabVIEW, then press the run button. (Some of the earlier answers taks about programmatically calling VIs, which I don't think is the focus of your question)
You can run as many VIs as you want at the same time. Simply press the run button of the second VI and they will both run.
Of course you should ensure that they don't use the same resources (e.g. DAQ device, or listen on the same TCP port, etc.) In these cases, the second VI might fail. (Also if the second VI is a subVI of the first VI, you won't be able to run it seperately, because it will be already running.)
LabVIEW Champion . Do more with less code and in less time .

Can I access two websites at the same time?

Does Dreamweaver have the ability to open two websites at the same time?
I basically have a CMS hosted on one server, that connects to my clients sites on other servers. I want to be able to open files on one server and edit them and also edit files on another server at the same time.
If this isn't available in Dreamweaver, then I think it should be. I often need to copy code from one page in a site to another page in different site. To have the ability to have two windows open, each connected to a different website server would be invaluable to me. By having separate windows, each can have its own server connection. I don't know how easy that would be, but I'd love it!
Cheers
Glynn

You can only connect to one site at a time. And you need to edit files locally, save & then upload to the remote server. AFAIK, no single FTP app is capable of connecting to more than one server at a time. You might be able to do what you want with DW open and an additional 3rd party FTP client like Filezilla, each connecting to different servers.
Nancy O.

How can I start two Vi at the same time?

I have two Vi's, each of these Vi has a stop button. I want to start these two Vis at the same time. I also want to be able to stop the two Vis at the same time. What should I do? Thanks.

One way to start them is with an Invoke Node and the Run method. You can then stop them with the Set Control Value [Variant] method. When you use the Set Control Value [Variant], you just have to specify the name of the front panel control that stops the while loop. Older versions of LabVIEW only had the Set Control Value method in which you had to use the flatten to string function to pass the Type Descriptor and Flattened Data.
Message Edited by Dennis Knutson on 03-20-200609:35 AM
Attachments:
Run Method.JPG ‏44 KB

Two profile two thunderbird at the same time with same user account

Dear,
I would use two Thunderbird at the same time for two different profiles with the same user accounts.
I using linux OS.
I was thinking of using:
# thunderbird -P profile1 &
# thunderbird -P profile2 &
But when launching the second command nothing happens.
Only brings in the foreground thundirbird already started.
If possible use this configuration now or in the nex future?

As a rule thunderbird only runs one instance of a profile.
However, there are a couple of options you could try.
You could use an addon to esily switch profiles:
* https://addons.mozilla.org/en-US/thunderbird/addon/profileswitcher/
there is more help here:
* http://kb.mozillazine.org/Run_multiple_copies_of_Thunderbird_at_the_same_time
It does say: 'Multiple instances is intended for debugging, so use it at your own risk'.
One method would be to use: Start > Run
"C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -no-remote -P profilename
there is a space before '-no'
and also before '-P'
followed by a space and the profile name
You could create a shortcut/icon to run each separate profile.

Blue Screen of Death of multiple Windows Multipoint Servers at the same time in NUServer64.sys

Hi, we are running
Windows MultiPoint Server 2011 on 4 Dell 9010 machines and 45 Wyse E02 clients connected by 4 switches. Every week we got 2 or 3 random BSoD for all servers at the same time. Memory dump for server 2,3,4 show that the exception is from NUServer64.sys.
Please check below for the system event logs and memory dump analysis output. Any help would be appreciated!
server1:
Warning 11/17/2013 8:55:52 PM
e1cexpress 27
None
Critical 11/17/2013 8:55:48 PM
Kernel-Power 41
(63)
Error 11/17/2013 8:56:08 PM
BugCheck 1001
None
The computer has rebooted from a bugcheck. The bugcheck was: 0x0000001e (0xffffffffc0000005, 0x0000000000000000, 0x0000000000000008, 0x0000000000000000). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 111813-19765-01.
Error 11/17/2013 8:56:03 PM
EventLog 6008
None
The previous system shutdown at 12:53:40 on 2013/11/18 was unexpected.
Error 11/17/2013 6:55:49 PM
Disk 11
None
The driver detected a controller error on \Device\Harddisk2\DR2.
Error 11/17/2013 6:55:48 PM
Disk 11
None
The driver detected a controller error on \Device\Harddisk2\DR2.
Warning 11/17/2013 3:42:08 PM
Microsoft-Windows-TerminalServices-Licensing
18 None
server2:
Warning 11/17/2013 8:55:39 PM
e1cexpress 27
None
Critical 11/17/2013 8:55:31 PM
Kernel-Power 41
(63)
Error 11/17/2013 8:55:52 PM
BugCheck 1001
None
The computer has rebooted from a bugcheck. The bugcheck was: 0x0000007e (0xffffffffc0000005, 0xfffff80002c80166, 0xfffff880023397e8, 0xfffff88002339040). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 111813-17518-01.
Error 11/17/2013 8:55:44 PM
EventLog 6008
None
The previous system shutdown at 12:53:53 on 2013/11/18 was unexpected.
Warning 11/17/2013 7:16:07 PM
NUServer64 3
None
server3:
Warning 11/17/2013 8:55:38 PM
Microsoft-Windows-TerminalServices-Licensing
18 None
Error 11/17/2013 8:55:31 PM
BugCheck 1001
None
The computer has rebooted from a bugcheck. The bugcheck was: 0x0000004e (0x000000000000009a, 0x0000000000417c94, 0x0000000000000006, 0x0000000000000002). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 111813-9937-01.
Warning 11/17/2013 8:55:24 PM
e1cexpress 27
None
Critical 11/17/2013 8:55:21 PM
Kernel-Power 41
(63)
Error 11/17/2013 8:55:27 PM
EventLog 6008
None
The previous system shutdown at 12:53:49 on 2013/11/18 was unexpected.
server4:
Warning 11/17/2013 8:55:33 PM
Microsoft-Windows-TerminalServices-Licensing
18 None
Warning 11/17/2013 8:55:09 PM
e1cexpress 27
None
Critical 11/17/2013 8:55:05 PM
Kernel-Power 41
(63)
Error 11/17/2013 8:55:25 PM
BugCheck 1001
None
The computer has rebooted from a bugcheck. The bugcheck was: 0x0000000a (0x0000000100000001, 0x0000000000000002, 0x0000000000000001, 0xfffff8000328abe6). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 111813-14055-01.
Error 11/17/2013 8:55:14 PM
EventLog 6008
None
The previous system shutdown at 12:53:21 on 2013/11/18 was unexpected.
Error 11/17/2013 8:51:47 PM
NUServer64 4
None
\Device\NUServer_995D6600
<995D6600_3> Disconnect fail.
Error 11/17/2013 8:51:47 PM
NUServer64 4
None
\Device\NUServer_995D6600
<995D6600_3> Connect fail.
Warning 11/17/2013 8:51:47 PM
NUServer64 3
None
\Device\NUServer_995D6600
<995D6600_3> Connect time-out.
Warning 11/17/2013 8:50:00 PM
NUServer64 3
None
\Device\NUServer_995B9000
<995B9000_3> Hi-Perf socket active clear.
Error 11/17/2013 8:49:25 PM
NUServer64 4
None
\Device\NUServer_995D6600
<995D6600_3> Disconnect fail.
Error 11/17/2013 8:49:25 PM
NUServer64 4
None
\Device\NUServer_995D6600
<995D6600_3> Connect fail.
Warning 11/17/2013 8:49:25 PM
NUServer64 3
None
\Device\NUServer_995D6600
<995D6600_3> Connect time-out.

Memory dumps:
server1:
2: kd> !analyze -v
* Bugcheck Analysis *
KMODE_EXCEPTION_NOT_HANDLED (1e)
This is a very common bugcheck. Usually the exception address pinpoints
the driver/function that caused the problem. Always note this address
as well as the link date of the driver/image that contains this address.
Arguments:
Arg1: ffffffffc0000005, The exception code that was not handled
Arg2: 0000000000000000, The address that the exception occurred at
Arg3: 0000000000000008, Parameter 0 of the exception
Arg4: 0000000000000000, Parameter 1 of the exception
Debugging Details:
EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
FAULTING_IP:
+3031623733386137
00000000`00000000 ?? ???
EXCEPTION_PARAMETER1: 0000000000000008
EXCEPTION_PARAMETER2: 0000000000000000
WRITE_ADDRESS: 0000000000000000
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
BUGCHECK_STR: 0x1E_c0000005
DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT
PROCESS_NAME: System
CURRENT_IRQL: 0
TRAP_FRAME: fffff8800c744860 -- (.trap 0xfffff8800c744860)
NOTE: The trap frame does not contain all registers.
Some register values may be zeroed or incorrect.
rax=0000000000000000 rbx=0000000000000000 rcx=0000000000000000
rdx=0000000000000000 rsi=0000000000000000 rdi=0000000000000000
rip=0000000000000000 rsp=fffff8800c7449f0 rbp=0000000000000000
r8=0000000000000000 r9=0000000000000f44 r10=fffff80003602000
r11=0000000000000358 r12=0000000000000000 r13=0000000000000000
r14=0000000000000000 r15=0000000000000000
iopl=0 nv up ei ng nz na pe nc
00000000`00000000 ?? ???
Resetting default scope
LAST_CONTROL_TRANSFER: from fffff800036c2738 to fffff80003677bc0
STACK_TEXT:
fffff880`0c743fd8 fffff800`036c2738 : 00000000`0000001e ffffffff`c0000005 00000000`00000000 00000000`00000008 : nt!KeBugCheckEx
fffff880`0c743fe0 fffff800`03677242 : fffff880`0c7447b8 00000000`00000030 fffff880`0c744860 00000000`00000000 : nt! ?? ::FNODOBFM::`string'+0x487ed
fffff880`0c744680 fffff800`03675dba : 00000000`00000008 00000000`00000000 00000009`00000000 00000000`00000030 : nt!KiExceptionDispatch+0xc2
fffff880`0c744860 00000000`00000000 : 00000000`00000030 ffffffff`fffe7960 00000000`00000000 00000000`00000000 : nt!KiPageFault+0x23a
STACK_COMMAND: kb
FOLLOWUP_IP:
nt! ?? ::FNODOBFM::`string'+487ed
fffff800`036c2738 cc int 3
SYMBOL_STACK_INDEX: 1
SYMBOL_NAME: nt! ?? ::FNODOBFM::`string'+487ed
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: nt
IMAGE_NAME: ntkrnlmp.exe
DEBUG_FLR_IMAGE_TIMESTAMP: 521ea035
FAILURE_BUCKET_ID: X64_0x1E_c0000005_nt!_??_::FNODOBFM::_string_+487ed
BUCKET_ID: X64_0x1E_c0000005_nt!_??_::FNODOBFM::_string_+487ed
Followup: MachineOwner
server2:
0: kd> !analyze -v
* Bugcheck Analysis *
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (7e)
This is a very common bugcheck. Usually the exception address pinpoints
the driver/function that caused the problem. Always note this address
as well as the link date of the driver/image that contains this address.
Arguments:
Arg1: ffffffffc0000005, The exception code that was not handled
Arg2: fffff80002c80166, The address that the exception occurred at
Arg3: fffff880023397e8, Exception Record Address
Arg4: fffff88002339040, Context Record Address
Debugging Details:
EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
FAULTING_IP:
nt!KeSetEvent+16
fffff800`02c80166 f6037f test byte ptr [rbx],7Fh
EXCEPTION_RECORD: fffff880023397e8 -- (.exr 0xfffff880023397e8)
ExceptionAddress: fffff80002c80166 (nt!KeSetEvent+0x0000000000000016)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 0000000000000000
Parameter[1]: 000000010f7f0a50
Attempt to read from address 000000010f7f0a50
CONTEXT: fffff88002339040 -- (.cxr 0xfffff88002339040)
rax=0000000000000000 rbx=000000010f7f0a50 rcx=0000000000000001
rdx=0000000000000000 rsi=fffffa800f7ec050 rdi=fffffa800f7ec1a0
rip=fffff80002c80166 rsp=fffff88002339a20 rbp=000000010f7f0a50
r8=0000000000000000 r9=0000000000000150 r10=fffff80002c06000
r11=fffff88002339a30 r12=0000000000000000 r13=fffffa800de82220
r14=fffffa800f7f0ae0 r15=0000000000000002
iopl=0 nv up ei ng nz na pe nc
cs=0010 ss=0000 ds=002b es=002b fs=0053 gs=002b efl=00010282
nt!KeSetEvent+0x16:
fffff800`02c80166 f6037f test byte ptr [rbx],7Fh ds:002b:00000001`0f7f0a50=??
Resetting default scope
DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT
PROCESS_NAME: System
CURRENT_IRQL: 0
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
EXCEPTION_PARAMETER1: 0000000000000000
EXCEPTION_PARAMETER2: 000000010f7f0a50
READ_ADDRESS: 000000010f7f0a50
FOLLOWUP_IP:
NUServer64+65f1
fffff880`0ab8c5f1 488b6c2448 mov rbp,qword ptr [rsp+48h]
BUGCHECK_STR: 0x7E
LAST_CONTROL_TRANSFER: from fffff8800ab8c5f1 to fffff80002c80166
STACK_TEXT:
fffff880`02339a20 fffff880`0ab8c5f1 : 00000000`000003f0 00000001`00000000 fffffa80`0f7ec000 00000000`00000500 : nt!KeSetEvent+0x16
fffff880`02339a90 fffff880`0ab8c8aa : fffffa80`0f7ec1a0 fffffa80`0f7eeb0c fffffa80`0f7ee2c8 00000000`00000002 : NUServer64+0x65f1
fffff880`02339ad0 fffff800`02f721d3 : fffffa80`0f7f0ae0 fffffa80`0f7ec260 fffffa80`0f7ec050 fffffa80`0c72e040 : NUServer64+0x68aa
fffff880`02339b40 fffff800`02c85261 : fffff800`02e21200 fffff800`02f72101 fffffa80`0c72e000 00000000`00000000 : nt!IopProcessWorkItem+0x23
fffff880`02339b70 fffff800`02f182ea : 501a7d4d`a14dcd79 fffffa80`0c72e040 00000000`00000080 fffffa80`0c70b6f0 : nt!ExpWorkerThread+0x111
fffff880`02339c00 fffff800`02c6c8e6 : fffff880`01f42180 fffffa80`0c72e040 fffff880`01f4d0c0 9ae0ec34`00b81aae : nt!PspSystemThreadStartup+0x5a
fffff880`02339c40 00000000`00000000 : fffff880`0233a000 fffff880`02334000 fffff880`02339370 00000000`00000000 : nt!KiStartSystemThread+0x16
SYMBOL_STACK_INDEX: 1
SYMBOL_NAME: NUServer64+65f1
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: NUServer64
IMAGE_NAME: NUServer64.sys
DEBUG_FLR_IMAGE_TIMESTAMP: 4f66a064
STACK_COMMAND: .cxr 0xfffff88002339040 ; kb
FAILURE_BUCKET_ID: X64_0x7E_NUServer64+65f1
BUCKET_ID: X64_0x7E_NUServer64+65f1
Followup: MachineOwner
server3:
0: kd> !analyze -v
* Bugcheck Analysis *
PFN_LIST_CORRUPT (4e)
Typically caused by drivers passing bad memory descriptor lists (ie: calling
MmUnlockPages twice with the same list, etc). If a kernel debugger is
available get the stack trace.
Arguments:
Arg1: 000000000000009a,
Arg2: 0000000000417c94
Arg3: 0000000000000006
Arg4: 0000000000000002
Debugging Details:
BUGCHECK_STR: 0x4E_9a
DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT
PROCESS_NAME: System
CURRENT_IRQL: 0
LAST_CONTROL_TRANSFER: from fffff80002d629ef to fffff80002cd3bc0
STACK_TEXT:
fffff880`14417968 fffff800`02d629ef : 00000000`0000004e 00000000`0000009a 00000000`00417c94 00000000`00000006 : nt!KeBugCheckEx
fffff880`14417970 fffff800`02e0403b : fffff880`14417a08 fffffa80`10cd1b88 fffff880`144179e0 00000000`000005a0 : nt!MiBadRefCount+0x4f
fffff880`144179b0 fffff800`02e078a7 : fffffa80`12894000 00000000`00000000 fffff6fb`7ea004a0 fffff800`00000001 : nt!MiFreePoolPages+0xa8b
fffff880`14417ac0 fffff880`0ad8d07a : 00000000`00000003 fffffa80`0f4471a0 fffffa80`36747345 fffffa80`00000000 : nt!ExFreePoolWithTag+0x7c7
fffff880`14417b70 fffff800`02f702ea : fffffa80`10cd1a80 00000000`00000080 fffffa80`0c70a740 003f005c`005c0000 : NUServer64+0x1707a
fffff880`14417c00 fffff800`02cc48e6 : fffff800`02e4ee80 fffffa80`10cd1a80 fffff800`02e5ccc0 00310026`00330023 : nt!PspSystemThreadStartup+0x5a
fffff880`14417c40 00000000`00000000 : fffff880`14418000 fffff880`14412000 fffff880`144174b0 00000000`00000000 : nt!KiStartSystemThread+0x16
STACK_COMMAND: kb
FOLLOWUP_IP:
NUServer64+1707a
fffff880`0ad8d07a 440f20c0 mov rax,cr8
SYMBOL_STACK_INDEX: 4
SYMBOL_NAME: NUServer64+1707a
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: NUServer64
IMAGE_NAME: NUServer64.sys
DEBUG_FLR_IMAGE_TIMESTAMP: 4f66a064
FAILURE_BUCKET_ID: X64_0x4E_9a_NUServer64+1707a
BUCKET_ID: X64_0x4E_9a_NUServer64+1707a
Followup: MachineOwner

Using the same object in two actors at the same time

Hello,
I'm in doubt. In my application, for example i have three Hardware classes - Database, DAQ1, DAQ2.
Database class has one main method (except initialization methods) - Log Measure.
DAQ1 class also has one method - Get Voltage, and DAQ2 class has one method - Get Current.
Then i define two HAL (Hardware Abstraction Layer) classes - Measurement1 and Measurement2.
Each of those classes have two main methods, respectively - Measure Voltage and Measure Curent. They also have some initilziation methods.
In code, i create three objects of Hardware classes - Database, DAQ1 and DAQ2 and initiaze it. For example in Database private cluster i have DB RefNum, in DAQ1&2 i have device addresses etc.
Next I initialzie Measurement1 with two hardware objects - Database and DAQ1, and in the same way - Measurement2 with Database, and DAQ2 objects.
What Measure Voltage and Measure Curent (methods of Measurement1 and Measurement1 objects) do?
Measure Voltage method call DAQ1::Get Voltage method, then Database::Log Measure.
Similarly, Measure Current method call DAQ2::Get Voltage method, then Database::Log Measure.
Till now it's clear i think. It should work properly.
But now i incorporate Actor Framework, and define Measurement1 and Measurement2 as an actors.
Now i can run Measurement1 and Measurement2 at the same time, simultaneously, but this two actors share one object - Database. So my question - what is when actors want to use Database::Log measure method at the same time and this method is time cosuming (for example large pack of data).
Is one actor waits for second to stop executing this method of one shared object? I think yes because reentrancy setting (http://zone.ni.com/reference/en-XX/help/371361J-01/lvconcepts/reentrancy/)
But what, for example if i share one Hardware object of device (ADC converter) beetwen two HAL classes (Measurement1 and Measurement2). This Hardware object has two methods, for ex. Get Voltage At channel 1, and Get Voltage At Channel 2. Both of this methods cannot by call at the same time, because in physical device i can measure only at one channel in the same time.
Let the Get Voltage At channel X meausere take 10 seconds. Now i have huge chance, that Measurement 1 actor call Get Voltage At channel 1 method, and Measurement 2 wants to call Get Voltage At channel 2, when Get Voltage At channel 1 is in process. How to inform actor to wait till second actor release device resources?
Regards,
Kacper

Dear Kacper,
the way I understood, there are two separate questions in this post, namely:
I'm using a shared resource in multiple actors, and the code accessing the resource can take quite some time to execute. How can can I ensure this does not mess up the timing of one or all accessors?
I'm using a shared resource in multiple actors, and the code accessing the resource can generate errors if I try to access it from multiple places. How can I ensure synchronization between all accessors?
As for the first question, the optimal solution to separate the resource prone to timing issues in a different thread/actor. Put anything that is not strictly timed (file access, network comunication) in a separate loop. For each actor, you will get queue references to communicate with, so instead of logging the measurements in the actors where they are made, just queue them up for a different loop to process.
For the second part, the same logic still applies. Ideally, every singular resource should be handled by its own thread and nowhere else, so if anything else needs data from/to said resource, it can send a request to the dedicated thread or actor.
If, for some reason, this is not sufficient, you have to handle synchronization in some other way. There are a lot of techniques here, for example:
Create a named semaphore or lock as a part of the class. Have class functions use the semaphore before accessing the resource.
Use actor messages. Have a "resource in use" or "resource released" messages sent to all users whenever obtaining or releasing said resource.
Have a separate actor handle all resources, awarding them to threads needing them. This method also allows setting priorities between requests.
These are just a few examples, there are many other options.
Please let me know if this was helpful.
Kind regards:
Andrew Valko
National Instruments Hungary

Can I shuffle two playlists at the same time?

How can I shuffle two playlists at the same time? Thank you.

You can only connect to one site at a time. And you need to edit files locally, save & then upload to the remote server. AFAIK, no single FTP app is capable of connecting to more than one server at a time. You might be able to do what you want with DW open and an additional 3rd party FTP client like Filezilla, each connecting to different servers.
Nancy O.

Can't start two listeners at the same time

Hello -
I am running Oracle 10g R2 on Solaris 10. I am getting the following error when I try to start my second listener "TNS-01106: Listener using listener name ccn_listener has already been started". There are multiple VIPA's assigned to the server, so I am trying to start two listeners at the same time (I can start each one separately). The different IP's are referenced in the listeners (even though they use port 1521), so there should not be a conflict. I also gave the two listeners distinct non-default names. The listeners are running under two differenct Oracle homes.
Here is the code of the listeners:
listener 1:
PHD_LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.49.236.119)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
SID_LIST_PHD_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u02/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
(SID_DESC =
(GLOBAL_DBNAME=phdv410g)
(ORACLE_HOME = /u02/app/oracle/product/10.2.0/db_1)
(SID_NAME = phdv410g)
listener 2:
CCN_LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.49.236.131)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
SID_LIST_CCN_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
(SID_DESC =
(GLOBAL_DBNAME=ccn10gt1)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(SID_NAME = ccn10gt1)
If anyone has any ideas about why I can't start these two listeners togethers, I would really appreciate it.
Thanks!

Hi,
Look at the error: "Listener already started"...
Can you check if that is right ?
ps -ef | egrep lsnrWaiting for feedback.
Regards,
Yoann.

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What do you think about running 2 security solutions at the same time? [malware event]

Hi all
Is there anyone here running 2 Security Solutions at the same time?
From what I know, few of my lecturers are running AVG and Avira, or Avira and MSE. (All free)
According to their theory, school-licensed Symantec Endpoint Protection slows down the system too much till a point that it is slow or unable to detect the threats. 1 antivirus is not good enough, 2 antivirus would be able to detect 100% of malware.
For my school labs computer, they are running both Symantec Endpoint Protection and Microsoft Security Essential at the same time.
Does 2 security solutions or more helps your computer to be risk-free?
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Mark it as solved if the solution works for you, so it could be reference for others in the future
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http://forums.lenovo.com/t5/W-Series-ThinkPad-Laptops/W520-Sound-Enhancement-Thread/m-p/451401#M155...
Solved!
Go to Solution.

Hello,
Generally speaking, you should not run two security programs together at the same time which run in "real-time," e.g., they are actively monitoring the system. The reason for this is that the various real-time components (on-access file system scanner, network traffic filter, and so forth) may interfere with each others operations as they both attempt to access the same bits at the same time. This can lead to all sorts of strange system behavior, such as slowdowns, program crashes, failed downloads and lock-ups.
If you are going to do this, make sure you disable the realtime scanning components of one program, or use one program to actively monitor the system and the other to periodically perform an scheduled or manual scans on demand.
Regards,
Aryeh Goretsky
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Generat two signals at the same time and reading voltage

Hii
i have try to generate two signals at the same time and read voltage from another port on the board(not have to be at the same time), i have not alot of expriens in labview
and i based my code of example(http://zone.ni.com/devzone/cda/epd/p/id/5197) from yours site and try to suit to my needs
now my problem is when i generat the 2 signals(that work perfect) i canot read voltage from another port on my CB-68LP
i can not find the problem and make it over i hope there is away to figer out and fix it.
i have two cards 6229, and two CB-68LP board.
labview 8.5.
my code is look like this - http://img142.imageshack.us/my.php?image=scrennshot2no2.png
(this works perfect).
and this is my code after suit to my need - http://img183.imageshack.us/my.php?image=scrennshotfl5.png,there is error exception at the right side.
the exception-
Possible reason(s):
Specified route cannot be satisfied, because it requires resources that are currently in use by another route.
Property: RefClk.Src
Source Device: Dev1
Source Terminal: 10MHzRefClock
Required Resources in Use by
Task Name: _unnamedTask<0>
Source Device: Dev1
Source Terminal: None
Destination Device: Dev1
Destination Terminal: RefClock
Task Name: _unnamedTask<1>
eyal

sorry...
The AO tasks is very important they will be synchronize ,it is very importent the two tasks will start at the same time
and after it run at synchronize mode i will need to make reading of voltage
i gust try to make simulation of machin (i give that machin AO and reading from it voltage that all)
first of all i make the two signals(synchronize signals).
and after it i will need to reading voltage.
i can make two signals synchronize together.
i can make reading voltage
but i can't make two signals synchronize together with reading voltage
it throw to me this error message.
i am looking for away to figer this out.
thank's for any help
eyal
Attachments:
test11.vi ‏130 KB

Write a progarm to test two parts at the same time

Hi:
I need to write a program in LabView that is capable of testing two parts at the same time.
Explanation:
I star the test on a unit, once all the electrical test is done move that unit to the pressure test without loosing the current test information and continue the test of the unit thewn generate a serial number only if it passes all the test. Then while the previous unit is going thru the pressure test star testing another unit for the elecrical test and so on.
I am using LabView 2012

From what you have described, I agree with what has been answered above. TestStand is specifically designed for. If you would like to provide more information about your application we could give you a more detailed response. For more information about TestStand follow this link
www.ni.com/teststand
Ryan
Ryan
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National Instruments

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