Abstract: A cached version of a file system directory is synchronized with a server version of the directory in a distributed file system. Both a server and a client specify version numbers for their directory versions. On receiving a request from the client specifying a directory update, the server updates its version, increments its version number, and transmits a reply to the client containing a change log with the incremented version number. Upon receiving the reply, the client compares the received version number with that of its cached version. If the version number matches that of the next expected update, the client applies the updates to its cached version and increments its version number. Otherwise, it adds the received change log to a change log queue for the directory without incrementing the last applied version. Mechanisms are provided for handling parallel read and update requests without awaiting replies from the server.

Abstract: Deadlock situations within a computing environment are avoided by properly managing pools of threads used to service requests of the computing environment. When a server of the computing environment receives a request to be processed and that request is waiting on a response from a client of the computing environment, the set of eligible thread pools for the response is dynamically altered. This dynamic altering allows the response to be serviced by a thread pool different from the thread pool servicing the request, thereby avoiding a deadlock situation.

Abstract: A cached version of a file system directory is synchronized with a server version of the directory in a distributed file system. Both a server and a client specify version numbers for their directory versions. On receiving a request from the client specifying a directory update, the server updates its version, increments its version number, and transmits a reply to the client containing a change log with the incremented version number. Upon receiving the reply, the client compares the received version number with that of its cached version. If the version number matches that of the next expected update, the client applies the updates to its cached version and increments its version number. Otherwise, it adds the received change log to a change log queue for the directory without incrementing the last applied version. Mechanisms are provided for handling parallel read and update requests without awaiting replies from the server.

Abstract: Data movement within a computing environment is at the very least reduced. Data is transmitted between a file system of the computing environment and a transmission medium of that environment. The transmission includes bypassing non-file system buffers in performing the transmission. For example, when data is sent to the file system to be written to one or more storage media, the file system swaps one or more buffers of the file system with the one or more buffers containing the data. The swapping does not require the copying of data. Further, for a read operation, the file system calls a routine, which is provided with one or more pointers to the data that is to be sent to a requester of the data.

Abstract: Data movement within a computing environment is at the very least reduced. Data is transmitted between a file system of the computing environment and a transmission medium of that environment. The transmission includes bypassing non-file system buffers in performing the transmission. For example, when data is sent to the file system to be written to one or more storage media, the file system swaps one or more buffers of the file system with the one or more buffers containing the data. The swapping does not require the copying of data. Further, for a read operation, the file system calls a routine, which is provided with one or more pointers to the data that is to be sent to a requester of the data.

Abstract: Deadlock situations within a computing environment are avoided by properly managing pools of threads used to service requests of the computing environment. When a server of the computing environment receives a request to be processed and that request is waiting on a response from a client of the computing environment, the set of eligible thread pools for the response is dynamically altered. This dynamic altering allows the response to be serviced by a thread pool different from the thread pool servicing the request, thereby avoiding a deadlock situation.

Abstract: Throughput of a request (e.g., a write request) is enhanced by allowing a receiver of the request to reply to the request before fully receiving the entire request. This reduces the delay between the time that the receiver completes a request and the time that the sender sees that the request is finished, and allows other requests to be forwarded prior to completion of the first request. The other requests that are forwarded, however, are processed in the order of receipt. Additionally, any errors that occur in a request after the reply is sent is forwarded to the sender of the request, even though the reply has previously been sent.

Abstract: Deadlock situations within a computing environment are avoided by properly managing pools of threads used to service requests of the computing environment. When a server of the computing environment receives a request to be processed and that request is waiting on a response from a client of the computing environment, the set of eligible thread pools for the response is dynamically altered. This dynamic altering allows the response to be serviced by a thread pool different from the thread pool servicing the request, thereby avoiding a deadlock situation.

Abstract: In a computing environment having clients with different semantics or protocols, a capability is provided that enables those clients to share the same data or files. A token management function is provided that allows clients that did not previously support token management to use the token management function to access the shared files. These capabilities are provided without requiring modifications to the client software.

Abstract: System and method for scheduling I/O requests in a multi-tasking data processing environment. An I/O request issued by an application is placed in an I/O request holding queue. Under control of the requesting application (or, alternatively, the operating system), the I/O request is selectively canceled or moved to a service pending queue for execution. Requests can be moved either by the application or by the Operating system when an I/O completes (and hence the service pending queue has room for another IO).