Abstract: In an embodiment, a request is received that includes data and a specification of a store operation, a key, and a local database. A predicted format for the data is determined based on a type of the requester and whether the local database is a primary database or a replica database. If the predicted format is a relational format, the data is converted to the relational format, if not already in the relational format, and stored into the local database. If a most-frequently predicted historical format is the relational format, the data is converted to the relational format, if not already in the relational format, and stored into the local database. If both the predicted format and the most-frequently predicted historical format are an object format, the data is converted into the object format, if not already in the object format, and stored into the local database.

Abstract: A method for handling service requests in a data processing system is disclosed. In response to a service request, a priority of the service request is determined by mapping a context of the service request to a service level agreement (SLA). SLA-aware and timeout-conscious and preemptive and replayable lock manager is designed to account for different operational goals and different importance to satisfy various SLAs. An average processing time of the service request is then calculated based on statistical results. The service request will be allowed to process if the determined average processing time meets historical guarantee situations.

Abstract: An apparatus, program product and method utilize on-demand clustering to handle client requests received by a clustered computer system. With on-demand clustering, clusters of nodes may be dynamically created in response to requests to perform work received from clients of a clustered computer system. By doing so, a clustered computer system often may be capable of adapting more easily to handle diverse and various types of workloads that may be unknown at the time of deployment of the clustered computer system.

Abstract: In an embodiment, data is partitioned into partitions, which are divided into levels. The levels are ordered by creation times of the levels. A request is received at a current partition, which includes a key that identifies a field in a record and a value for the key. A determination is made whether the value exists in the field in the current partition. If the determination is false, a message is sent from the current partition to a next-older partition, and the message instructs the next-older partition to move the record with the value from the next-older partition to the current partition. If the determination is true, the record with the value in the field is moved from the current partition to a next-newer partition if the next-newer partition sent the request, and the record is deleted from the current partition.

Abstract: In an embodiment, in response to a request, a connection is selected from a pool of connections to a server. If the connection is stale and the number of stale connections encountered is greater than an adaptive threshold, then recovery is performed on all of the connections in the pool. If the number of stale connections is not greater than the adaptive threshold, then recovery is performed on the stale connection. A decision is made whether the connection is stale by sending the request to the server via the connection and detecting whether the sending encountered an error and by receiving a response from the server via the current connection and detecting whether the response indicates that the request encountered an error at the server. The recovery of all of the connections in the pool includes sending a ping message to the server on each of the connections and removing the connections from the pool for which the ping message is unsuccessful.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, accumulate multiple work units into a bundle and send the bundle to a selected active server. The active server is selected based on the relative costs for the work units and costs for servers. In an embodiment, selecting the active server includes determining relative work unit costs and relative server costs, calculating total weighted costs for the servers based on the relative work unit costs and the relative server costs, and selecting the active server that has the lowest total weighted cost. The active server may either process a work in the bundle locally or send the work unit to a passive server for processing. The active server determines whether each work unit can be executed at the active server. If the work unit can be executed on the active server, the active server executes the work unit and creates local results.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, send a broadcast message to a cluster of servers receive a point-to-point message from a coordinating server of the cluster, where the coordinating server joined the cluster before all other servers in the cluster. The point-to-point message includes routing data regarding all of the servers in the cluster. In an embodiment, the broadcast message includes a record that includes an identification of a new server, resource data regarding the new server, and a time that the new server joins the cluster, and the servers in the cluster add the record to the routing data and send a request to the new server via the record. In another embodiment, the broadcast message includes records for all servers in a second cluster, and the new server sends the routing data to the servers in the second cluster. If a server leaves the cluster, its record is removed.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, receive a change request from a first client at a first time, where the change request includes a key that identifies a field in a data object. A determination is made that the first client changed the field identified by the key at a second time that is before the first time and that a second client changed the field identified at a third time that is after the second time and before the first time, and the key is sent to the second client. The client receives the key, and in various embodiments invalidates the key in a cache or removes the key from the cache. In an embodiment, the data value of the change request is also sent to the second client, which updates the cache with the data value. In this way, stale data in a cache at a client is either updated or removed.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, route requests to servers based on a synchronization level of data that the servers provide. In an embodiment, synchronization levels that servers provide are determined, a synchronization level that a request requires is determined, a server is selected based on the provided synchronization levels and the required synchronization level, and the request is routed to the selected server. The selection of the server may include selecting a subset of the servers, ordering the subset based on the provided synchronization levels, and selecting the highest synchronization level that is processing less than a threshold number of requests.

Abstract: A method, distributed-computing system, and computer program product for providing efficient workload management within a distributed computing environment. Each device within the distributed-computing environment is enhanced with a workload management controller (WLMC) functionality/utility, designed specifically for the type of device (i.e., client WLMC versus server WLMC) and utilized to collect process data about the particular device (e.g., status information) and about the device's interaction with the network. With the localized device-based WLM Controllers, each device utilizes fully distributed tagged information to accomplish capacity-based routing, context-based routing, and resource-based routing without any overhead or loss of data and without any network congestion. The distributed WLM Controller model enables each device to operate without concern for the level of CPU usage or memory usage of the particular device.

Abstract: In a networked computer system, partitioned proxies are defined that each include a cache of connection information that allows for quickly routing a remote invocation to an object without suffering the overhead of determining routing information for the object each time the object is remotely invoked. Multiple copies of an object are created in multiple computer systems. A partitioned proxy is then created that points to each copy of the object. The partitioned proxies allow quickly accessing these object copies without the overhead of synchronizing their state data. Caching connection information within the partitioned proxies allows a computer system to invoke a remote object without the performance penalty of determining with each invocation the connection information for accessing the remote object.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, receive a request and an associated universal partition context, determine a destination application server partition based on a context of the request and a partitioning scheme, and route the request and the universal partition context to the destination server partition. The destination application server partition may be further determined based on creating a partition key from the context via the partitioning scheme and by accessing a unified partition configuration that is associated with the destination application server partition via the partition key. The unified partition configuration is determined from the universal partition context.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, determine an application server partition based on the context of a request from a client, and send the request to the application server partition if the application server partition exists. If the application server partition does not exist, the application server partition is created based on a creation rule, and the request is then sent to the application server partition if the request context is valid, as determined by a validation rule. Periodically, a remove rule is compared to a condition of the application server partition, and if the remove rule is met, the application server partition is removed. The condition may include, in various embodiments, the usage time and frequency of use of the application server partition or performance criteria. In an embodiment, the validation rule, the creation rule, and the remove rule may change over time.

Abstract: A method, apparatus, system, and signal-bearing medium that, in an embodiment, collect previous and current statistics based on previous and current access plans, respectively, and a query. The previous and current statistics are compared in response to an event, and the differences between the previous and current statistics are presented. In various embodiments, the event may be a change to logic in a database management system that performs the query, a degradation in performance of the query, or a user request. In various embodiments, the difference may be a change to the previous access plan that causes performance degradation of the query, such as missing an index. The previous access plan is copied into the current access plan if an estimated processing time for the current access plan is greater than an estimated processing time for the previous access plan. The current access plan is used to perform the query.