Jon A Lind

US Patent:

7373647, May 13, 2008

Filed:

Apr 30, 2003

Appl. No.:

10/427385

Inventors:

David C. Kalmuk - Toronto, CA
Jon A Lind - Beaverton OR, US
Hebert W. Pereyra - Toronto, CA
Xun Xue - Markham, CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9/44

US Classification:

719317, 719312

Abstract:

An operating system directed to using special properties of a common inter-process communications mechanism (IPC), namely UNIX domain socket-pairs or stream-pipes alternatively as a storage medium for file-descriptors of UNIX processes. When a file-descriptor is written into a socket-pair, and closed in the UNIX process, the file remains open, but occupies no space in the process' file-table. The file-descriptor may later be read out of the socket-pair to reestablish it in the file-table, and access it. This property is implemented in an IPC mechanism of UNIX operating system whereby a process such as a dispatcher may manage more connections and processes than its file-table size allow. This provides scalability improvements of the UNIX operating system.

US Patent:

7669080, Feb 23, 2010

Filed:

Aug 16, 2007

Appl. No.:

11/839739

Inventors:

Jon A. Lind - Beaverton OR, US
Dale M. McInnis - Aurora, CA
Steven R. Pearson - Portland OR, US
Steve Raspudic - Mississauga, CA
Vincent Kulandaisamy - Portland OR, US
Yuke Zhuge - Portland OR, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 11/00

US Classification:

714 11, 714 5

Abstract:

A method, system, and computer program product for reducing likelihood of data loss during performance of failovers in a high-availability system comprising a primary system and a standby system are provided. The method, system, and computer program product provide for defining a halt duration, periodically determining a halt end time, halting data modifications at the primary system responsive to failure of data replication to the standby system, resuming data modifications at the primary system responsive to a last determined halt end time being reached or data replication to the standby system resuming, and responsive to the primary system failing prior to a previously determined halt end time, determining that a failover to the standby system will not result in data loss on the standby system with respect to the primary system.

US Patent:

7844974, Nov 30, 2010

Filed:

Apr 17, 2008

Appl. No.:

12/105032

Inventors:

David C. Kalmuk - Toronto, CA
Jon A. Lind - Beaverton OR, US
Hebert W. Pereyra - Toronto, CA
Xun Xue - Markham, CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9/44

US Classification:

719317, 719312

Abstract:

An operating system directed to using special properties of a common inter-process communications mechanism (IPC), namely UNIX domain socket-pairs or stream-pipes alternatively as a storage medium for file-descriptors of UNIX processes. When a file-descriptor is written into a socket-pair, and closed in the UNIX process, the file remains open, but occupies no space in the process' file-table. The file-descriptor may later be read out of the socket-pair to reestablish it in the file-table, and access it. This property is implemented in an IPC mechanism of UNIX operating system whereby a process such as a dispatcher may manage more connections and processes than its file-table size allow. This provides scalability improvements of the UNIX operating system.

US Patent:

7934220, Apr 26, 2011

Filed:

Mar 17, 2008

Appl. No.:

12/049991

Inventors:

David C. Kalmuk - Toronto, CA
Jon A Lind - Beaverton OR, US
Hebert W. Pereyra - Toronto, CA
Xun Xue - Markham, CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9/44
G06F 15/16

US Classification:

719317, 719312, 709202

Abstract:

An operating system directed to using special properties of a common inter-process communications mechanism (IPC), namely UNIX domain socket-pairs or stream-pipes alternatively as a storage medium for file-descriptors of UNIX processes. When a file-descriptor is written into a socket-pair, and closed in the UNIX process, the file remains open, but occupies no space in the process' file-table. The file-descriptor may later be read out of the socket-pair to reestablish it in the file-table, and access it. This property is implemented in an IPC mechanism of UNIX operating system whereby a process such as a dispatcher may manage more connections and processes than its file-table size allow. This provides scalability improvements of the UNIX operating system.

US Patent:

20040122953, Jun 24, 2004

Filed:

Apr 14, 2003

Appl. No.:

10/412428

Inventors:

David Kalmuk - Toronto, CA
Jon Lind - Beaverton OR, US
Hebert Pereyra - Toronto, CA
Xun Xue - Markham, CA

Assignee:

International Business Machines Corporation

International Classification:

G06F015/16
G06F017/30
G06F007/00

US Classification:

709/227000, 707/010000

Abstract:

A communications multiplexor includes dispatcher processes for monitoring client connections. The dispatcher processes detect activity on those connections, and then pass active physical (client) connections to agent processes for servicing. Transfer is done through specific connection queues that are associated with a set of agents. A multi-queuing structure permits pooling of agents on a set of shared resources thereby reducing time required to switch between different client connections. After an agent has serviced a given connection, the agent returns that connection to the agent's dispatcher (there is a static assignment between connections and dispatchers), and then reads the next unit of work from the agent's associated connection queue. This structure may be scalable while allowing optimal performance when passing physical connections between processes.