c# - SharePoint Web Part & Singletons -

i have sharepoint project override search box , other things. have web part page responds search box. these components should share single configuration. thought creating singleton, not sure how ever cleaned / removed memory / uninstalled.

any ideas? warnings using singletons in sharepoint? also, there proper way share instance of object between these componenets?

edit: thinking simple singleton. configuration needs contain 5-20 strings , dozen integers @ most. no complex objects :)

as long objects being managed singleton class thread-safe there shouldn't issue.

example:
have series of object-calls taking long-time process (7+ seconds). so, decided try using comet-styled long-polling technique process them. such, host service (as static singleton) in single thread , process requests using asynchronous httphandler's...and works great! , because i'm using service asynchronously it's highly efficient because calling thread gets released (upon completion of processing service completes callback).

edit:
problem of long processing time still exists, still (probably) need asynchronous solution initial fetch. hows this? why not combine asych-solution custom-caching?

for various (accessibility) reasons, save appsetting's in database , use custom-cache access thereafter.

example of custom cache:

public enum configurationsection {     appsettings }  public static class utility {     #region "common.configuration.configurations"      private static cache cache = system.web.httpruntime.cache;      public static string getappsetting(string key)     {         return getconfigurationvalue(configurationsection.appsettings, key);     }      public static string getconfigurationvalue(configurationsection section, string key)     {         configurations config = null;          if (!cache.trygetitemfromcache<configurations>(out config))         {             config = new configurations();             config.list(snclavalin.us.common.enumerations.configurationsection.appsettings);             cache.addtocache<configurations>(config, datetime.now.addminutes(15));         }          var result = (from record in config                       record.key == key                       select record).firstordefault();          return (result == null) ? null : result.value;     }      #endregion }  namespace common.configuration {     public class configurations : list<configuration>     {         #region constructors          public configurations() : base()         {             initialize();         }         public configurations(int capacity) : base(capacity)         {             initialize();         }         public configurations(ienumerable<configuration> collection) : base(collection)         {             initialize();         }          #endregion          #region properties & fields          private crud _crud; // db-access layer          #endregion          #region events         #endregion          #region methods          private void initialize()         {             _crud = new crud(utility.connectionname);         }          /// <summary>         /// lists one-to-many records.         /// </summary>         public configurations list(configurationsection section)         {             using (dbcommand dbcommand = _crud.db.getstoredproccommand("spa_list_secconfiguration"))             {                 _crud.db.addinparameter(dbcommand, "@section", dbtype.string, section.tostring());                  _crud.list(dbcommand, populatefrom);             }              return this;         }          public void populatefrom(datatable table)         {             this.clear();              foreach (datarow row in table.rows)             {                 configuration instance = new configuration();                 instance.populatefrom(row);                 this.add(instance);             }         }          #endregion     }      public class configuration     {         #region constructors          public configuration()         {             initialize();         }          #endregion          #region properties & fields          private crud _crud;          public string section { get; set; }         public string key { get; set; }         public string value { get; set; }          #endregion          #region events         #endregion          #region methods          private void initialize()         {             _crud = new crud(utility.connectionname);             clear();         }          public void clear()         {             this.section = "";             this.key = "";             this.value = "";         }         public void populatefrom(datarow row)         {             clear();              this.section = row["section"].tostring();             this.key = row["key"].tostring();             this.value = row["value"].tostring();         }          #endregion     } }