when you move a conversation to a conversation group, that conversation_group has to have been created previously, ie, you cant specify a non-existing conversation_group, right?
I ask because I am trying to develop an application where I use optimally one conversation related to many given conversation_groups, so that when I receive, I lock only a small determined subset of messages. What I could have used was a way to send messages on a conversation, specifying a conversation_group_id.
I'm using service broker and keep getting errors in the log even though everythig is working as expected
SQL Server 2005 Two databases Two end points - 1 in each database Two stored procedures: SP1 is activated when a message enters the sending queue. it insert a new row in a table SP2 is activated when a response is sent from the receiving queue. it cleans up the sending queue.
I have a table with an update trigger In that trigger, if the updted row meets a certain condition a dialogue is created and a message is sent to the sending queue. I know that SP1 and SP2 are behaving properly because i get the expected result. Sp1 is inserteding the expected data in the table SP2 is cleaning up the sending queue.
In the Sql Server log however i'm getting errors on both of the stored procs. error #1 The activated proc <SP 1 Name> running on queue Applications.dbo.ffreceiverQueue output the following: 'The conversation handle is missing. Specify a conversation handle.'
error #2 The activated proc <SP 2 Name> running on queue ADAPT_APP.dbo.ffsenderQueue output the following: 'The conversation handle is missing. Specify a conversation handle.'
I would appreceiate anybody's help into why i'm getting this. have i set up the stored procs in correctly?
i can provide code of the stored procs if that helps.
My service broker was working perfectly fine earlier. As I was testing...I recreated the whole service broker once again.
Now I am able to get the message at the server end from intiator. When trying to send message from my server to the intiator it gives this error in sql profiler.
broker:message undeliverable: This message could not be delivered because the Conversation ID cannot be associated with an active conversation. The message origin is: 'Transport'.
broker:message undeliverable This message could not be delivered because the 'receive sequenced message' action cannot be performed in the 'ERROR' state.
We have implemented our service broker architecture using conversation handle reuse per MS/Remus's recommendations. We have all of the sudden started receiving the conversation handle not found errors in the sql log every hour or so (which makes perfect sense considering the dialog timer is set for 1 hour). My question is...is this expected behavior when you have employed conversation recycling? Should you expect to see these messages pop up every hour, but the logic in the queuing proc says to retry after deleting from your conversation handle table so the messages is enqueued as expected?
Second question...i think i know why we were not receiving these errors before and wanted to confirm this theory as well. In the queuing proc I was not initializing the variable @Counter to 0 so when it came down to the retry logic it could not add 1 to null so was never entering that part of the code...I am guessing with this set up it would actually output the error to the application calling the queueing proc and NOT into the SQL error logs...is this a correct assumption?
I have attached an example of one of the queuing procs below:
Code Block DECLARE @conversationHandle UNIQUEIDENTIFIER, @err int, @counter int, @DialogTimeOut int, @Message nvarchar(max), @SendType int, @ConversationID uniqueidentifier select @Counter = 0 -- THIS PART VERY IMPORTANT LOL :) select @DialogTimeOut = Value from dbo.tConfiguration with (nolock) where keyvalue = 'ConversationEndpoints' and subvalue = 'DeleteAfterSec' WHILE (1=1) BEGIN -- Lookup the current SPIDs handle SELECT @conversationHandle = [handle] FROM tConversationSPID with (nolock) WHERE spid = @@SPID and messagetype = 'TestQueueMsg'; IF @conversationHandle IS NULL BEGIN BEGIN DIALOG CONVERSATION @conversationHandle FROM SERVICE [InitiatorQueue_SER] TO SERVICE 'ReceiveTestQueue_SER' ON CONTRACT [TestQueueMsg_CON] WITH ENCRYPTION = OFF; BEGIN CONVERSATION TIMER ( @conversationHandle ) TIMEOUT = @DialogTimeOut -- insert the conversation in the association table INSERT INTO tConversationSPID ([spid], MessageType,[handle]) VALUES (@@SPID, 'TestQueueMsg', @conversationHandle);
SEND ON CONVERSATION @conversationHandle MESSAGE TYPE [TestQueueMsg] (@Message)
END ELSE IF @conversationHandle IS NOT NULL BEGIN SEND ON CONVERSATION @conversationHandle MESSAGE TYPE [TestQueueMsg] (@Message) END SELECT @err = @@ERROR; -- if succeeded, exit the loop now IF (@err = 0) BREAK; SELECT @counter = @counter + 1; IF @counter > 10 BEGIN -- Refer to http://msdn2.microsoft.com/en-us/library/ms164086.aspx for severity levels EXEC spLogMessageQueue 20002, 8, 'Failed to SEND on a conversation for more than 10 times. Error %i.' BREAK; END -- We tried on the said conversation, but failed -- remove the record from the association table, then -- let the loop try again DELETE FROM tConversationSPID WHERE [spid] = @@SPID; SELECT @conversationHandle = NULL; END;
I have a system that will post a message to a queue, but does not need to wait for a response - just needs to make sure the message arrived properly in the queue, not that is was processed at the receiving end. A second service will poll the queue to retrieve outstanding messages and will then move the message to an outside system. The movement of the message to the outside system will be wrapped in a transaction and if the process is successful, then the transaction will be commited otherwise it will be rolled back.
1) is it appropriate for the service that posts the message to send an END CONVERSATION ? This way the sending service will not be waiting for a response.
2) in the data movement phase, is it appropriate to issue and END CONVERSATION when commiting and not issue when ROLLBACK occurs. Or should ROLLBACK occur with a following END CONVERSATION with error message?
I am attempting to learn Service Broker from Bob Beauchemin's book "A Developer's Guide to SQL Server" - Chapter 11. I'm finding it to be very good but I'm confused over the concept of closing a conversation. Could someone answer the following questions for me?
When a conversation is ended, can the conversation handle that was created when the conversation was created still be used? (I assume not) Beauchemin says, on page 511, that when a conversation ends, "Any messages still in the queue from the other end of the conversation are deleted with no warning." Does this mean that if I send a message that expects a reply, but I end the conversation, the message is still sent, it is still received by the other endpoint, the other endpoint processes it, but I'll never receive the reply? Beauchemin says that if no lifetime is specified, the conversation is active for the number of seconds which can be represented by the maximum size of an integer. Does this mean that if I don't specify a lifetime, a conversation is active for many, many years?
I want to reuse conversations to minimize overhead during bursts of activity. Remus' article on reusing conversations (http://blogs.msdn.com/remusrusanu/archive/2007/05/02/recycling-conversations.aspx) is great. (I know you are reading this Remus, thanks.)
I was wondering if there is a simpler way of ending a cached conversation - Quiesce the conversation (Stop using it), then after some period of time, end it.
I create a conversation, cache it in RLY_Conversations, and use it for 50 seconds. After 1 minute, the dialog timer servicing proc ends the conversation. There will be no messages sent around the time the End Conversation takes place, thus no race conditions.
Do you see any problems with this method?
Select @DialogHandle = [conversation_handle] From RLY_Conversations Where TableName = @TableName and IsActive = 1 And
CreatedTmstp > dateadd(ss, -50, getdate())
if @DialogHandle is null Begin -- initialize a conversation and record it in our reuse table BEGIN DIALOG CONVERSATION @DialogHandle FROM SERVICE FirstHostRelayService TO SERVICE 'SecondHostRelayService' ON CONTRACT RelayContractSentByAny WITH ENCRYPTION=OFF ;
-- cache the dialog handle to minimize dialog creation overhead. Insert into RLY_Conversations ( TableName, conversation_handle, conversation_id, is_initiator, service_contract_id, conversation_group_id, service_id, lifetime, state, state_desc, IsActive, CreatedBy, CreatedTmstp ) Select @TableName, conversation_handle, conversation_id, is_initiator, service_contract_id, conversation_group_id, service_id, lifetime, state, state_desc, 1, 'Setup', getdate() From sys.conversation_endpoints Where conversation_handle = @DialogHandle;
-- initiate housekeeping process BEGIN CONVERSATION TIMER ( @DialogHandle ) TIMEOUT = 60; End
Message ordering is of utmost importance in our application.
As i found in testing the only way to ensure message ordering is if they are in the same conversation.If you send multiple messages in different conversations there is no garantee which will be processed first.
Therefore i will be creating conversations that last "forever", that is using a single conversation.
I plan on doing a BEGIN DIALOG CONVERSATION when an inititator site is setup and writing the conversation handle guid to a table.
I will them simply SEND ON SONVERSATION using the guid, i will never issue a end conversation from target or initiator.
Is this theory solid, ie: is there a better way or best practice to do this?
I know that conversatons persist with sql server restarts, however what happens if an initiator site db is restored ?
I was thinking of adding logic to first check if a conversation endpoint exists with the specified guid if not , then start another conversation. But is this the best way?
I am thinking of updating my SQL monitoring application to use Service Broker.
Right now I loop through my list of servers performing various checks on each server. Things like 'check last database backup', 'check for new databases', 'check for server restart'. I loop through, one server at a time, doing one check at a time. The more servers I have the longer it is taking.
So, I want to multi-thread the servers, but single-thread the checks on each individual server. This way I can check say, 5 servers at a time, but on each server I will only do one check at a time. This way I won't flood an individual server with multiple checks.
Is this possible? It looks like Conversation groups might be the way to go but I'm not sure.
I'm having some troubles with conversation groups. I need to send two messages on the same conversation group so I have the following in my SP....
BEGIN DIALOG CONVERSATION @providerConversationHandle FROM SERVICE [ProviderDataService] TO SERVICE 'CalculatedDataService' ON CONTRACT [ProviderDataContract] WITH ENCRYPTION = OFF , LIFETIME = 600;
BEGIN DIALOG CONVERSATION @curveConversationHandle FROM SERVICE [ProviderDataService] TO SERVICE 'CalculatedDataService' ON CONTRACT [ProviderDataContract] WITH RELATED_CONVERSATION = @providerConversationHandle , ENCRYPTION = OFF , LIFETIME = 600;
SEND ON CONVERSATION @providerConversationHandle MESSAGE TYPE [ProviderDataMessage] ( @providerMessage );
SEND ON CONVERSATION @curveConversationHandle MESSAGE TYPE [ProviderCurveMessage] ( @curveMessage );
When I query the queue I see two messages, but they don't have the same conversation_group_id.
I have not been successfull in getting conversation group to work. My understanding is that I can specify a 'guid' for a conversation group id in the create dialog and when I send a message on this conversation it will have that specific guid for its conversation group. When I do this it does not appear this way in the "target" queue.
I am looking for an example to help me understand how to use a conversation group. The MSDN has not really provided that run able example that I can run and verify and tweak.
The idea that I would like to try is that the initiator must send 5 different XML messages to a target. These 5 messages are all related and must exist together. What I assume is that if I want the target to get all 5 messages together out of the queue all messages must be sent in their own conversation but all linked with the same conversation group Id. I have not been able to get this to work.
The communication is really a one way where the initiator sends the data to the target and does not process or need a message sent back from the target.
I have a conversation that I want to know has not ended so I am using LIFETIME.
When the conversation times out I then have three records in the queue.
1. The original conversation record that has not been received.
2. Error message to the initiator.
3. Error message to the target.
Both message bodies on the error records say that it was a lifetime error.
If I end the conversation on the initiator side after it is sent, I still get the target error record but the message_body field is null.
So say I don't end the conversation on the initator side. My next receive on the target side will pull the original record. Then it will pull the initator record and then it will pull the target record. Nothing on that record says that it had timed out.
What is the best practice for handling lifetime errors?
END CONVERSATION DIALOG CONVERT(uniqueidentifier, '58C1A7AA-C0D7-DB11-B4C6-005056C00008')
using ICommand.Execute method, I got an error:
Incorrect syntax near the keyword 'END'.
I use SQL Native Client as OLE DB Provider.
In profiler I can see that my statement becomes like this:
exec END CONVERSATION CONVERT(uniqueidentifier, '903586ED-C0D7-DB11-B4C6-005056C00008')
So provider add 'exec' before my statement, maybe because NCLI don't know such statetment and thinks that it is a stored procedure call with the name 'END'?
Is there is a way to avoid it except of using following construction:
I am new to service broker and would like a little help please. I have a SP which gathers information from a collection of tables. Depending on the data gathered it may or may not begin a dialog conversation with a service broker queue. What i'm needing to know is should at the end of the SP once the required message has been sent should i end the conversation or not?
Given that the conversation states are as follows: (Thanks Rushi!)
Event Initiator Endpoint state Target Endpoint state
BEGIN DIALOG SO -- from Initiator to Target
SEND message(s) CO -- from Initiator to Target
Target receives a fragment CO SI of the first message sent or receives out of order message
Target received entire CO CO first message
END conversation at CO DO target
Initiator receives EndDialog DI DO message from target
Target receives ACK for the DI CD EndDialog message sent
END conversation at CD CD Initiator
When does the 30 minute timer start for clearing the conversation from the sys.conversation_handles table? Is it the same for both sides (initiator and Target) ie, the end conversation at the Initiator. I guess it must be just in case a resend is necessary.
I was trying to clean up some conversation in Service Broker and caused alot of blocking that I seem to unable to kill. there was 1 conversation that I was not able to end, so I wanted to restart sql service, But I can't even restart the SQL service. I get the following in Event Viewer
Timeout occurred while waiting for latch: class 'SERVICE_BROKER_TRANSMISSION_INIT', id 00000001A2B03540, type 2, Task 0x0000000000C2EDA8 : 0, waittime 5400, flags 0xa, owning task 0x00000002DEBCA5C8. Continuing to wait.
Is there a DMV or something in the system that can tell me what the current queue message number is for a conversation.
I would like to determine what the message queue_order number for a message is before or after i send the message, as i would like to log this information?
I have read the articles posted online concerning different dialog reuse strategies. Most of them create a new table in the sender to hold dialog ids. I was wondering what is wrong, if anything, with the following approach:
Code Block declare @dlg uniqueidentifier select top 1 @dlg = conversation_handle from sys.conversation_endpoints where state IN ('CO') if @dlg is null begin begin dialog conversation @dlg from service [tcp://SFT3DEVSQL01:4022/TyMetrix360Audit/DataSender] to service '//TyMetrix360Audit/DataWriter','386DDD04-7E55-466A-BE83-37EFC20910B9' on contract [//TyMetrix360Audit/Contract] with encryption = off; end ;send on conversation @dlg message type [//TyMetrix360Audit/Message] (@msg)
Here I simply select a conversation handle directly from the sys.conversation_endpoints table. Can anyone see any issues with this approach?
Using conversation timers, I would like to send a message to myself. I could then use the self-addressed message to check on the availability of a provider. What would be the recommended approach for doing this using the ServiceBrokerInterface? It seems that I might need to add a method to the Service class. Is it correct? Thanks,
I'm trying to use Service Broker to relate a set of messages together and was trying to use a related conversation group id. From what I can gather (looking at other threads) I can't use this.....
Basically, my ideas was.... I have several tables being updated within a database transaction. These tables will have triggers associated with them which send a message to a SB queue detailing the table that has been affected and the key information.
After the database transaction commits, I wanted to retrieve the group of messages in order to identify exactly what happened to the database during the transaction (for business reasons). I don't need necessarily need them in the same order, but do need them grouped by database transaction.
Service Broker seemed to be ideal i.e. the messages wouldn't commit if the database transaction rolled back and I wouldn't be able to access them until the entire transaction was committed........ My only problem is that I don't seem to be able to associate them with each other!!!!
Can anyone help with a way I can do this with Service Broker, or am I just trying to use the wrong technology???
set @date = (select dateadd(day,0,getdate())) set @day = (select datepart(day,@date)) set @month = (select datepart(month,@date)) set @year = (select datepart(year,@date)) set @tarih = (select '''' + @year + '-' + @month + '-' + @day + ' 00:00:00.000''' )
if @month < 10 begin set @month = '0' + @month end if @day < 10 begin set @day = '0' + @day end -------------IT GIVES ERROR HERE set @dateS = (select '''' + @year + '-' + @month + '-' + @day + ' 00:00:00.000''' )
--- well , when i try this > set @date (which is datetime format ) = '2008-03-22 00:00:00.000' it works(manually), but i cant dynamically bind my string to datetime formatted field.
then i tried, set @dates = (select '''' + @year + @month + @day + '''' ) set @date = (select convert(datetime,@dates)
I have a replicated table that has a trigger attached to the it. The trigger fires off a service broker message for inserts. Originally for every insert, I would begin a conversation, send, and end the conversation when target send an end conversation. Since replication process is only using a single spid, I would like to reuse 1 conversation. the following is what I have for the send procedure in the initiator. I check the conversation_endpoints for any open conversation, if it's null, I start a new conversation and send else just send with the existing conversation. Is there anything wrong with this code? What could cause the conversation on the initiator to be null if I never end the conversation on the initiator side? thanks
DECLARE @dialog_handle uniqueidentifier
select @dialog_handle = conversation_handle from sys.conversation_endpoints where state = 'CO'
What is actually happening when a conversation timer is being used in terms of the dialog_timer column in sys.conversationendpoints? For example, I was using the following query to tell me which conversation timers are currently running:
SELECT * FROM sys.conversation_endpoints
WHERE dialog_timer > '1900-01-01 00:00:00.000'
However, I have noticed that periodically the dialog_timer value goes back to '1900-01-01 00:00:00.000' and the query fails, starting up another timer. Then, the original timer magically appears again, working just fine. So, I changed to this query:
SELECT * FROM sys.conversation_endpoints
WHERE far_service
IN
(
'TimerService1',
'TimerService2',
'TimerService3',
)
But this seems like the long way around and doesn't really indicate that the timer is running or not, just that its present in the sys.conversationendpoints catalog view. What is the proper way to see if timers are running? If one dies for some reason, I need to restart it.
I am ending conversations properly for a dialog, the end conversation at the target properly marks the conversation as closed in sys.conversation_endpoints and sends the EndDialog message to the initiator.
The initiator get the EndDialog message from the target and ends the conversation and it clears out of sys.conversation_endpoints.
I know that to avoid reply attacks that the conversation at the target will only clear out in 30 minutes.
However it has been a day now and the conversation is still sitting in sys.conversation_endpoints as CLOSED at the target.
How do i troubleshoot this ? Why is the conversation not clearing?
I have a service broker setup between 2 remote server. The message send does get sent to the target, but I am having a problem where the end conversation message from the target is failing. I did a trace on both the target and the source server. here's what I found
On the Target Server:
on Broker: Message undeliverable --- This message could not be delivered because it is a duplicate
On the Source Server
on Broker: Message undeliverable --- This message could not be delivered because the security context could not be retrieved,
I do not understand why the message is delivered, but the end conversation message is not getting thru. On the Target transmission_queue. I have millions of messages like this
We are using service broker between two different instances. But were facing issues with increasing row count in conversation_endpoints view. We found that this was because we were using default value for lifetime for the conversation which is value of size int. Later on we changed the lifetime to 1 minute and conversation_endpoints view start getting cleaned up after 30 minutes
Following commands are used to send message
Before :
BEGIN DIALOG CONVERSATION @handle FROM SERVICE @SendService TO SERVICE @ReceiveService ON CONTRACT @Contract SEND ON CONVERSATION @handle MESSAGE TYPE @xmlMessageType(@xmlMessage);
END CONVERSATION @handle;
After:
BEGIN DIALOG CONVERSATION @handle FROM SERVICE @SendService TO SERVICE @ReceiveService ON CONTRACT @Contract WITH LIFETIME = @lifetime;
SEND ON CONVERSATION @handle MESSAGE TYPE @xmlMessageType(@xmlMessage);
END CONVERSATION @handle;
But as we use default life time for a long due to which around 15 million records got acumlated in this view. What is the best way to clean up this view.
END Conversation @handle with cleanup is taking so long is their any other way to do this
Looking in a various resources, i see that a conversation group guarantees receiving messages EOID, which means that each message will be received only once, and that messages will be received in the order they were sent.
However, the documentation explicitly states that only dialogs guarantee messages order. So, I€™m a little bit confused, what's the "In-Order" stand for in "Exactly Once In Order"?
I'm using conversation timers successfully to fire events at a predetermined time in the future, but I'm running into issues when using an interval of considerable size. I set the conversation timeout like so:
set @Timeout = DATEDIFF(SECOND, GETDATE(), DATEADD(MINUTE, -(@TimeOffset), @FollowUpDateTime));
if (@Timeout < 0)
set @Timeout = 1;
// begin dialog
begin conversation timer (@FollowUpConversation)
timeout = @Timeout;
In this case @Timeout was 94693494.
In the SQL error log I see the following error: "Invalid subcommand value 94693494. Legal range from 1 to 2147483."
I thought I may check the @Timeout value and simply set it to 2147483 if it is larger than 2147483, but I was wondering if there was a reason the upper limit was so small.
I'd like to add code to a trigger to calculate the time to fire a message into a queue based on a field changing, and conversation timers seem like the way to go. My first question refers to this line from the BOL:
"Calling BEGIN CONVERSATION TIMER on a conversation before the timer has expired sets the timeout to the new value."
I think that in this trigger, I can simply begin a new conversation if the given field has changed to reset the timer. But intuition tells me that in order to change the timer to a new value, I need to retrieve the existing conversation, correct?
Also, I've read that conversation timers are persistent in that they survive database restarts and shutdowns. But I'm not sure to what extent. After a database restart/shutdown, does the conversation timer "reset" itself to the time interval specified when the conversation was begun or is it able to account for the time the database was down/offline?
