sql server - NHibernate session.flush() fails but makes changes -

-

We have a SQL Server database table that contains User ID, some numeric values, e.g. Balance, and a version column.

We have multiple threads which update the value column of this table in parallel, each in its own transaction and session (we are using the session-per-thread model). Since we all want logical transactions, each thread follows:

  1. Load the existing line (map for one type).
  2. Make changes to the value, based on the old value (for example 50 add).
  3. session.update (obj)
  4. session.flush () (Because we are optimistic, we want to make sure that we had the correct version value earlier
  5. If Step 4 (Flush) threw StaleStateException, refresh the object (with lockmode.read) and goto Step 1

We only make it count of a certain per logical transaction If we can not do this after X efforts, then we reject logical transactions.

Each such thread is time-consuming For example, to keep committed-driven I / O at manageable levels after 100 successful logical transactions, meaning - we have a single database transaction (per transaction), which is very low with many flush There is a logical change at least once.

What is the problem here, you ask? Ok, but we see changes in the failed logical objects. Specifically, if the value was 50, when we did step 1 ( First time) to go through A, and we tried to update it to 100 (but we failed because as another thread changed it to 70), then the value of 50 is that this line is obviously wrong. It is wrong.

What are we missing here?

Well, I do not have a ton of experience here, but one thing to remember is that if If there is an exception, you want to immediately withdraw the transaction and want to settle the session. Maybe your problem relates to the session that occurs in an inconsistent state?

Also, here is the call to update the update in your code. Since you loaded the object in that session, it is already being tracked by nhibernate.


Comments

Post a Comment

Popular posts from this blog

c# - How to capture HTTP packet with SharpPcap -

-
I would like to capture all incoming HTTP packets on my machine. To do this, I am using SharpPcap which is a WinPcap The cover is. SharpPcap works very well, but it captures TCP packets and what it wants to do for me is a very low level. Does anyone know how can I easily get full HTTP requests / reactions from all these TCP packets? Thanks SharpPcap is already able to capture the packet in the same way That's what the virus does (just in the code instead of the GUI). And you can either either parse them directly or you can put them in the drive in the common .pcap file format. The steps to parse the capture are: Open a connection at any time Loop a while Or start capturing using an event callback Parsing the raw packet for the type you want If you are reading .PPP dump files In addition to calling you an offline capture reader is almost the same, there is no need to select an interface, and you can set the majority There is no need to do the modes. All st
Read more

jquery - SimpleModal Confirm fails to submit form -

-
I am trying to confirm jQuery to show yes / no confirmation when I submit a form. I had modified (in the last list) to capture and block form submissions. However, it only works with jQuery 1.2.6, a recent upgrade stops 1.3.2, if yes is clicked, then by submitting the form. But I can not understand what is wrong / inconsistent in my code now. Demo (which works in both versions of a simple window.href implementation). $ (document) .ready (function () {$ ('input.delete'). Click (function (e) {e.preventDefault (); var target = $ (e .target); Confirm ("Really delete this event?", Function () {target.click ()});});}); How about something like this? The idea of ​​catching clicks (and fire!) On the submitted event is not click event. $ (document) .ready (function () {$ ('# myForm'). Submit (function () {var f = this; Confirm (" Remove? ", Function () {$ (f). Submit ();}) Return; Return the initial session;}}}}; Hope That this is som
Read more

php - Multiple Select with Explode: only returns the word "Array" -

-
By using Wordpress I have created a multiple selection box so that users can select categories to exclude. When the page is initially loaded, I see my predefined default option. However, when I select a new value and I save ... I only see the word "Array" and have not chosen anything else? & lt; Class = "amultiple" id = "& lt; php echo $ value ['id'] ;? gt;" name = "& gt; php echo $ value ['id'] ;; gt; []" Multiple = "multiple" size = "8" & gt; & Lt ;? Php global option; Foreign currency ($ value as value $) {if (get_settings ($ value ['id']) === FALSE {$$ value ['id'] = $ value ['std']; } And {$$ value ['id'] = get_settings ($ value ['id']); }} $ Ranges = & amp; Amp; Categories ('type = post & orderbiz = name & amp; hide_empty = 1'); If ($ ranges) {$ ex_cat = implode (',', $ tt_cat_exclude); Forex Currency ($ range a
Read more