locking

I have an ASP.Net MVC application that uses SQL Server 2005 via NHibernate. I am getting getting the following error message sporadically: "System.Data.SqlClient.SqlException (0x80131904): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning() at System.Data.SqlClient.TdsParser

memcached can be used for a caching static data which reduces database lookup and typically does memcached.get(id) and memcached.set(id) . However is it fine to use this for locking mechanisms? Does memcache.set and memcached.get always give the data if it is present or will it just return None if the request is taking too much time? I want to avoid concurrent access to a particular resource identified by a id and I use this logic: def access(id): if memcache.get(id): return access else: memcache.set(id) return true If any user tries to access that resource, if memcache.get(id) = username

I would like to make a simple locking mechanism in Python without having to rely on the existing libraries for locking (namely fcntl and probably others) I already have a small stub, but after searching for a bit I couldn't find a good on answer on how to manually create the lock file and put the process PID inside. Here is my stub: dir_name = "/var/lock/mycompany" file_name = "myapp.pid" lock = os.path.join(dir_name, file_name) if os.path.exists(lock): print >> sys.stderr, "already running under %s, exiting..." % lock # display process PID contained in the file, not relevant to my question

For last 48 hours, I have been trying to understand Multithreading and Socket Programming . I tried to implement socket programming and had success when not using multithreading. I am new to both of the topics and have raised 2-3 question on stack itself needing help on the same. After googling a lot I found an article that explains Socket Programming and Multithreading , but I still have a lot of doubts in this article and got stuck at Figure 5 in the article. private void AcceptConnections() { while (true) { // Accept a connection Socket socket = _serverSocket.Accept(); ConnectionInfo

I have a simple table in Sybase, let's say it looks as follows: CREATE TABLE T ( name VARCHAR(10), entry_date datetime, in_use CHAR(1) ) I want to get the next entry based on order of "entry_date" and immediately update "in_use" to "Y" to indicate that the record is not available to the next query that comes in. The kicker is that if two execution paths try to run the query at the same time I want the second one to block so it does not grab the same record. The problem is I've found that you cannot do "SELECT FOR UPDATE" in Sybase if you have an ORDER BY clause, so the following stored proc

i want to open my created lock instead of default one,when phone is boot at that time my lock is called. But i want to know when my screen on after locked at that time how i called my lock (my lock activity)Means i want to display my lock instead of default at time of screen on or phone restart or switch on all time. like in our phone lock called all time same as i want to call my lock all time( done with boot ).so please any one help me how i call my lock when screen on/off.please help quickly thanks.... i do for boot time call my lock following exactly i that i want for screen-on/off {