I have a rather complex and large database with about 3000+ objects (tables/triggers/sps combined). I inherited this DB and restructuring it is probably 3-4 years away.
meanwhile, I need to implement a pub sub feature for any insert/update/delete on these tables. Given number of tables and existing queries probably query notification (and SQL Dependency) will not work. What I am looking for is a way to push the changes (what changed in table - like records PK and table name) on the service broker so I can use external activator to then retrieve change,and then use my custom pub sub from that point onwards.
I have pretty much all the ducks lined up except for the way to push change notification on service broker.
Any help/pointers are appreciated.
Thanks.
N M
PS. I did look around for similar postings and did come across a few however, MSDN articles they referred to seem to have all removed - not sure what's going on on MSDN site.
For external activator look at Microsoft SQL Server 2008 Feature Pack- "Microsoft SQL Server 2008 R2 Service Broker External Activator".
For console application (that processes messages) great idea is to drop an eye in codeplex. There is good examples.
To put event notification (notifications, that will be used by external activator service) code looks something like this:
Create Queue ExternalActivatorQueue;
Create Service ExternalActivatorService On Queue ExternalActivatorQueue
([http://schemas.microsoft.com/SQL/Notifications/PostEventNotification])
Create Event Notification NotifyExternalActivator
On Queue dbo.ProcessQueue
For QUEUE_ACTIVATION
To Service 'ExternalActivatorService', 'current database'
To send message in the queue:
Declare #h UniqueIdentifier;
Declare #x xml = '<tag/>';
Begin Dialog Conversation #h
From Service MyTableService
To Service 'ProcessService'
With Encryption = OFF;
Send On Conversation #h(#x)
All steps i done to make it work is here, but just in Latvian :). There actually is almost what you need (trigger that sends messages when data are inserted in table..).
Related
I am trying to connect my Soffid 3 server with our custom web application named Schrift. I am using а JSON REST Web Services Connector for this purpose. I added REST Web service plugin and then configured an agent with JSON/XML/SOAP Rest webservice type.
Loading of objects is working fine. My REST connector connects to the web service successfully and gets data of the accounts.
The problem is when I am trying to update some data (for example, I am trying to lock an account), nothing happens. And unfortunately I don't know what should be happening. When should REST connector send updated data to the managed system and in which way? I didn't find any log entries saying that REST connector was trying to update an object on managed system. Maybe I did smth wrong or missed something.
I would appreciate for any help. I can post any conf or log details if you need.
Update#1
(I did some investigation after the first answer)
I checked the agent settings: Read only and Manual account creation are set to no
The account was set to unmanaged type, but I succeeded in changing its type to shared and then to single without getting an error. Now it is set to single
The task queue is empty.
Also I've checked that update method is present and update properties are set correctly. updateParams is not set (it means that all attributes should be sent to the managed system).
But when I change status of the account (from Enable to Disable), nothing happens.
In the console log I can see only these lines
14-Sep-2021 13:26:29.708 INFO [BPM-Scheduler:192.168.7.121:1] com.soffid.iam.bpm.job.JobExecutorThread.run No job to execute
When I manually run the task Analize impact for changes on Schrift, Execution log shows
Changes detected for accounts
=============================
NO CHANGE DETECTED
Changes detected for roles
=============================
NO CHANGE DETECTED
Update#2
After many attempts I made some progress. Now when I make some changes in the account, the task named UpdateAccount baklykov#irf.com.ua#Schrift appears, but runs with an error.
At first it was 415 Unsupported Media Type error as I wrote in comments, but now it looks a little different
Throws exception updating object : Extensible object [type = account]
EmployeeEmail: baklykov#irf.com.ua
IsLockedOut: true (log truncated) ...
caused by Unexpected response, Content-Type: null
Update#3
I found out that soffid's request for updating the object was in improper format (all the parameters were passed in the html request instead of putting them in json body)
After researching I found a method's property called Encoding and set it to application/json value.
Now the parameters are passed in json body (that's what I need), but now the problem is that soffid puts all the parameters in json body, including the key parameter by which the object for updating should be determined. My guess this is the reason why the object in the target system is still not updated.
In other words my application expects a request like this:
https://myapp.mysite.com/api/v1/Soffid/Employees?EmployeeEmail=baklykov%40irf.com.ua :
{"EmployeeLastName":"Baklykov","EmployeeFirstName":"Ivan"}
but Soffid sends this:
https://myapp.mysite.com/api/v1/Soffid/Employees:
{"EmployeeLastName":"Baklykov","EmployeeFirstName":"Ivan","EmployeeEmail":"baklykov#irf.com.ua"}
The system should have created a UpdateAccount task in the task queue. Please, verify:
The task engine is in automatic mode. In read-only or manual mode, no task will be created.
If you are updating an account, check the account is not set as unmanaged. In that case, no tasks is created.
Finally, verify the task queue has not held the task up.
Have you checked the engine mode? Look at Main Menu > Administration > Configure Soffid > Integration engine > Smart engine settings
It should be set to automatic.
I am new to using peoplesoft/peoplecode and have a question if anybody could help. We have a web service that will let you insert values that will be stored into Table A on Database A. I am trying to use integration broker so that when that Table is being updated on Database A, the same exact table will be updated on Database B. On the service for Database A, I have made a rowset message containing the table, the que for it, the service and service operation. The service operation routes the message to the local node on Database B and uses a application class handler to insert data into the table. For some reason, when I go to the web service to add a row to the table, no message is put into the q. It seems to not notice that I am trying to send it to the other database(Database B), but it does update Database A. Any ideas of stuff I can check to fix this error, or do I need to set something up on the service for Database B? Thank you.
Shawn, creating the message definitions and services are not enough.
You have to write some peoplecode to trigger the WS for you.
If you have done that, please share the code so we can check for the error. If not, do it ;)
Is there an equivalent of PostgresQL's notify and listen in MySQL? Basically, I need to listen to triggers in my Java application server.
Ok, so what I found is that you can make UDF functions in mysql that can do anything but need to be written in C/C++. They can be then called from triggers on updates in database and notify your application when update happened. I saw that there are some security concerns. I did not use it myself but from what I can see it looks like something that could accomplish what you want to do and more.
http://dev.mysql.com/doc/refman/5.6/en/adding-udf.html
The github project mysql-notification provides a MySQL user defined function MySQLNotification() as a plugin to MySQL that will send notification events via a socket interface. This project includes a sample NodeJS test server that receives the notification events that could be adapted for Java or any other socket service.
Example use:
$ DELIMITER ##
$ CREATE TRIGGER <triggerName> AFTER INSERT ON <table>
FOR EACH ROW
BEGIN
SELECT MySQLNotification(NEW.id, 2) INTO #x;
END##
Project includes full source code and installation instructions for OSX and Linux. License is GNU v3.
No, there aren't any built-in functions like these yet.
You need to "ping" (every 1-5 seconds) database with selecting with premade flag like "read" 0/1. After
SELECT * FROM mytable WHERE read = 0
update it with read = 1
I needed to do this, so I designed my application to send the update notices itself.
E.g.
--Scenario--
User A is looking at record 1
User B saves an update to record 1 while User A has it open.
Process:
I wrote my own socket server as a Windows Service. I designed a que like system which is basically,
EntityType EntityID NoticeType
Where the EntityType is the type of Poco in my data layer that needs to send out notices, EntityID is the primary key value of the row that changed in sql (the values of the poco), and NoticeType is 1 Updated, 2 Inserted, and 3 Deleted.
The socket server accepts connections from the server side application code on a secure connection "meaning client side code cannot make requests designed to be sent by the server side application code"
The socket server accepts a message like
900 1 1023 1
Which would mean the server needs to notify concerned client connections that Entity Type 1 "Person" with ID 1023 was Updated.
The server knows what users need to be notified because when User's look at a record, they are registered in the socket server as having an interest in the record and the record's ID which is done by the web socket code in the client side javascript.
Record 1 is a POCO in my app code that has an IsNew and IsDirty field. "Using EntityFrameWork6 and MySql" If UserB's save caused an actual change (and not just saving existing data) IsDirty will be true on the postback on UserB's POCO.
The application code see's the record is dirty then notifies the socket server with a server side sent socket "which will be allowed" that says Entity 1 with ID 1023 was Updated.
The socket server sees it, and puts it in the que.
Being .Net, I have a class for concerned users that uses the same pocos from the data layer running in the Socket Server window service. I use linq to select users who are working with an entity matching the entity type and primary key id of the entity in the que.
It then loops through those users and sends them a socket like
901 1 1023 1 letting them know the entity was updated.
The javascript in the client side receives it causing users B's page to do an ajax postback on Record 1, But what happens with UserA's is different.
If user A was in the process of making a change, they will get a pop up to show them what changed, and what their new value will be if they click save and asks them which change they want to keep. If UserA doesn't have a change it does an ajax postback with a notification bar at the top that says "Record Change: Refreshed Automatically" that expires after a few seconds.
The Cons to this,
1. It's very complex
2. It won't catch insert/update/delete operations from outside of the application.
In my case, 2 won't happen and if 2 does happen it's by myself or another dev who knows how to manually create the notify que requests "building an admin page for that".
You can use https://maxwells-daemon.io to do so.
It is based on mysql bin logs, when changes in database is occurred it will send json message with updates to kafka, rabbitmq or other streaming platforms
I have recently started development on a relatively simple WCF REST service which returns JSON formatted results. At first everything worked great, and the service was quickly up and running.
The main function of the service is to return a large chunk of data extracted from a database. This data rarely changes, so I decided to try and setup a caching mechanism to speed things up. To do this I planned to set InstanceContextMode.Single and ConcurrencyMode.Multiple, and then with some thread locks, safely return a static cached result. Every 5 minutes or so, or whenever IIS decides to clear everything, the data would be re-fetched from the database.
My issue is InstanceContextMode.Single does not behave as expected. My understanding is a single instance of my WCF service class should be created and maintained. However the behaviour I have is a completely new instance of my Class is created per call. This include re-initialising all static variables.
I tried changing the web service from webHttpBinding (used for REST) to wsHttpBinding and using the service as a SOAP config, but this results in exactly the same behaviour.
What am I doing wrong!!! Have spent way too long trying to figure this out.
Any help would be great!.
Strange, can you try this and tell me what happen then?
ServiceThrottlingBehavior ThrottleBehavior = new ServiceThrottlingBehavior();
ThrottleBehavior.MaxConcurrentSessions = 1;
ThrottleBehavior.MaxConcurrentCalls = 1;
ThrottleBehavior.MaxConcurrentInstances = 1;
ServiceHost Host = ...
Host.Description.Behaviors.Add(ThrottleBehavior);
And [how] do you know your single service instance isn't "Single"? You saw multiple database connection from profiler? Is that what suggested to you why your service isn't a single instance? From your service operation implementation, do you do some of the work on a separate thread?
I'm looking for a way to create a simple HTML table that can be updated in real-time upon a database change event; specifically a new record added.
In other words, think of it like an executive dashboard. If a sale is made and a new line is added in a database (MySQL in my case) then the web page should "refresh" the table with the new line.
I have seen some information on the new using EVENT GATEWAY but all of the examples use Coldfusion as the "pusher" and not the "consumer". I would like to have Coldfusion both update / push an event to the gateway and also consume the response.
If this can be done using a combination of AJAX and CF please let me know!
I'm really just looking to understand where to get started with real-time updating.
Thank you in advance!!
EDIT / Explanation of selected answer:
I ended up going with #bpeterson76's answer because at the moment it was easiest to implement on a small scale. I really like his Datatables suggestion, and that's what I am using to update in close to real time.
As my site gets larger though (hopefully), I'm not sure if this will be a scalable solution as every user will be hitting a "listener" page and then subsequently querying my DB. My query is relatively simple, but I'm still worried about performance in the future.
In my opinion though, as HTML5 starts to become the web standard, the Web Sockets method suggested by #iKnowKungFoo is most likely the best approach. Comet with long polling is also a great idea, but it's a little cumbersome to implement / also seems to have some scaling issues.
So, let's hope web users start to adopt more modern browsers that support HTML5, because Web Sockets is a relatively easy and scalable way to get close to real time.
If you feel that I made the wrong decision please leave a comment.
Finally, here is some source code for it all:
Javascript:
note, this is a very simple implementation. It's only looking to see if the number of records in the current datatable has changed and if so update the table and throw an alert. The production code is much longer and more involved. This is just showing a simple way of getting a close to real-time update.
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.js"></script>
<script type="text/javascript" charset="utf-8">
var originalNumberOfRecsInDatatable = 0;
var oTable;
var setChecker = setInterval(checkIfNewRecordHasBeenAdded,5000); //5 second intervals
function checkIfNewRecordHasBeenAdded() {
//json object to post to CFM page
var postData = {
numberOfRecords: originalNumberOfRecsInDatatable
};
var ajaxResponse = $.ajax({
type: "post",
url: "./tabs/checkIfNewItemIsAvailable.cfm",
contentType: "application/json",
data: JSON.stringify( postData )
})
// When the response comes back, if update is available
//then re-draw the datatable and throw an alert to the user
ajaxResponse.then(
function( apiResponse ){
var obj = jQuery.parseJSON(apiResponse);
if (obj.isUpdateAvail == "Yes")
{
oTable = $('#MY_DATATABLE_ID').dataTable();
oTable.fnDraw(false);
originalNumberOfRecsInDatatable = obj.recordcount;
alert('A new line has been added!');
}
}
);
}
</script>
Coldfusion:
<cfset requestBody = toString( getHttpRequestData().content ) />
<!--- Double-check to make sure it's a JSON value. --->
<cfif isJSON( requestBody )>
<cfset deserializedResult = deserializeJSON( requestBody )>
<cfset numberOFRecords = #deserializedResult.originalNumberOfRecsInDatatable#>
<cfquery name="qCount" datasource="#Application.DBdsn#" username="#Application.DBusername#" password="#Application.DBpw#">
SELECT COUNT(ID) as total
FROM myTable
</cfquery>
<cfif #qCount.total# neq #variables.originalNumberOfRecsInDatatable#>
{"isUpdateAvail": "Yes", "recordcount": <cfoutput>#qCount.total#</cfoutput>}
<cfelse>
{"isUpdateAvail": "No"}
</cfif>
</cfif>
This isn't too difficult. The simple way would be to add via .append:
$( '#table > tbody:last').append('<tr id="id"><td>stuff</td></tr>');
Adding elements real-time isn't entirely possible. You'd have to run an Ajax query that updates in a loop to "catch" the change. So, not totally real-time, but very, very close to it. Your user really wouldn't notice the difference, though your server's load might.
But if you're going to get more involved, I'd suggest looking at DataTables. It gives you quite a few new features, including sorting, paging, filtering, limiting, searching, and ajax loading. From there, you could either add an element via ajax and refresh the table view, or simply append on via its API. I've been using DataTables in my app for some time now and they've been consistently cited as the number 1 feature that makes the immense amount of data usable.
--Edit --
Because it isn't obvious, to update the DataTable you call set your Datatables call to a variable:
var oTable = $('#selector').dataTable();
Then run this to do the update:
oTable.fnDraw(false);
UPDATE -- 5 years later, Feb 2016:
This is much more possible today than it was in 2011. New Javascript frameworks such as Backbone.js can connect directly to the database and trigger changes on UI elements including tables on change, update, or delete of data....it's one of these framework's primary benefits. Additionally, UI's can be fed real-time updates via socket connections to a web service, which can also then be caught and acted upon. While the technique described here still works, there are far more "live" ways of doing things today.
You can use SSE (Server Sent Events) a feature in HTML5.
Server-Sent Events (SSE) is a standard describing how servers can initiate data transmission towards clients once an initial client connection has been established. They are commonly used to send message updates or continuous data streams to a browser client and designed to enhance native, cross-browser streaming through a JavaScript API called EventSource, through which a client requests a particular URL in order to receive an event stream.
heres a simple example
http://www.w3schools.com/html/html5_serversentevents.asp
In MS SQL, you can attach a trigger to a table insert/delete/update event that can fire a stored proc to invoke a web service. If the web service is CF-based, you can, in turn, invoke a messaging service using event gateways. Anything listening to the gateway can be notified to refresh its contents. That said, you'd have to see if MySQL supports triggers and accessing web services via stored procedures. You'd also have to have some sort of component in your web app that's listening to the messaging gateway. It's easy to do in Adobe Flex applications, but I'm not sure if there are comparable components accessible in JavaScript.
While this answer does not come close to directly addressing your question, perhaps it will give you some ideas as to how to solve the problem using db triggers and CF messaging gateways.
M. McConnell
With "current" technologies, I think long polling with Ajax is your only choice. However, if you can use HTML5, you should take a look at WebSockets which gives you the functionality you want.
http://net.tutsplus.com/tutorials/javascript-ajax/start-using-html5-websockets-today/
WebSockets is a technique for two-way communication over one (TCP) socket, a type of PUSH technology. At the moment, it’s still being standardized by the W3C; however, the latest versions of Chrome and Safari have support for WebSockets.
http://html5demos.com/web-socket
Check out AJAX long polling.
Place to start Comet
No, you can't have any db code execute server side code. But you could write a service to poll the db periodically to see if a new record has been added then notify the code you have that needs pseudo real-time updates.
The browser can receive real-time updates via BOSH connection to Jabber/XMPP server. All bits and pieces can be found in this book http://professionalxmpp.com/ which I highly recommend. If you can anyhow send XMPP message upon record addition in your DB, then it is relatively easy to build the dashboard you want. You need strophe.js, Jabber/XMPP server (e.g. ejabberd), http server for proxying http-bind requests. All the details can be found in the book. A must read which I strongly believe will solve your problem.
The way I would achieve the notification is after the database update has been successfully committed I would publish an event that would tell any listening systems or even web pages that the change has occurred. I've detailed one way of doing this using an e-commerce solution in a recent blog post. The blog post shows how to trigger the event in ASP.NET but the same thing can easily be done in any other language since ultimately the trigger is performed via a REST API call.
The solution in this blog post uses Pusher but there's not reason why you couldn't install your own real-time server or use a Message Queue to communication between your app and the realtime server, which would then push the notification to the web page or client application.