公开(公告)号：GB2326802B

公开(公告)日：2002-05-01

申请号：GB9809607

申请日：1998-05-07

Applicant: IBM

Inventor： DIAS DANIEL MANUEL ,  IYENGAR ARUN KWANGIL

IPC: G06F13/00 ,  G06F15/00 ,  G06F21/20 ,  G06F15/16 ,  G06Q30/00 ,  H04L29/06 ,  H04L29/08 ,  G06F17/30 ,  H04L9/32

Abstract: In a client-server environment having a server group including one or more participating servers and one or more controller servers, where each participating server can communicate with at least one controller server, a method for coordinating actions among the servers in the server group comprising the steps of: (1) communicating between a client and at least one of the servers in the server group using a protocol that has limited or no defined procedures for passing state information between the client and the servers; (2) transmitting a request for an action from the client to one of the servers; and (3) communicating among a plurality of servers with at least one controller server coordinating actions of at least some of the servers in response to the request. A preferred embodiment of the method includes providing client identification information once by the client during a conversation, verifying the client identification information by one or more controller servers, generating client authentication information by one or more controller servers that is preserved in the conversation, and using the preserved client authentication information to automatically authenticate the client during the remainder of the conversation. Another preferred embodiment of the method includes transmitting a request by a client requiring participation by a plurality of servers and communicating among the servers with at least one controller server coordinating the actions of a plurality of servers in response to the request from the client.

公开(公告)号：HU0003427A2

公开(公告)日：2001-02-28

申请号：HU0003427

申请日：1998-05-27

Applicant: IBM

Inventor： DIAS DANIEL MANUEL ,  JHINGRAN ANANT DEEP ,  KING RICHARD PERVIN ,  POLYZOIS CHRISTOS

IPC: G06F11/14

公开(公告)号：PL337021A1

公开(公告)日：2000-07-31

申请号：PL33702198

申请日：1998-05-27

Applicant: IBM

Inventor： DIAS DANIEL MANUEL ,  JHINGRAN ANANT DEEP ,  KING RICHARD PERVIN ,  POLYZOIS CHRISTOS

IPC: G06F11/14

公开(公告)号：CA2288016A1

公开(公告)日：1998-12-03

申请号：CA2288016

申请日：1998-05-27

Applicant: IBM

Inventor： DIAS DANIEL MANUEL ,  JHINGRAN ANANT DEEP ,  KING RICHARD PERVIN ,  POLYZOIS CHRISTOS

IPC: G06F11/14

Abstract: A method and system for recovering from a failure of a processing node in a partitioned shared nothing database processing system are provided. The processing system may include a pair of processing nodes having twin-tailed-connected thereto a storage device. A first processing node of the pair of processing nodes has a first database instance running thereon which accesses a first data partition on the storage device prior to the failure. Upon detection of the failure, access to the first data partition on the storage device is provided to a third, spare processing node through the second processing node of the pair of processing nodes. The third processing node runs a replacement database instance for the first database instance which was running on the first processing node prior to the failure thereof. The replacement database instance accesses the first data partition on the storage device through the second processing node, thereby recovering from the failure of the first processing node. Access to the first data partition may include using a virtual shared disk utility having a server portion on the second processing node and a client portion on the third processing node.

公开(公告)号：SG42854A1

公开(公告)日：1997-10-17

申请号：SG1996000149

申请日：1994-07-15

Applicant: IBM

Inventor： POLYZOIS CHRISTOS ALKIVIADIS ,  DIAS DANIEL MANUEL ,  BHIDE ANUPAM KESHAV

IPC: G06F11/20 ,  G06F3/06 ,  G06F12/00 ,  G06F12/16 ,  G11B27/00 ,  G11C29/00

Abstract: A fault-tolerant high performance mirrored disk subsystem is described which has an improved disk writing scheme that provides high throughput for random disk writes and at the same time guarantees high performance for disk reads. The subsystem also has an improved recovery mechanism which provides fast recovery in the event that one of the mirrored disks fails and during such recovery provides the same performance as during non-recovery periods. Data blocks or pages which are to be written to disk are temporarily accumulated and sorted (or scheduled) into an order (or schedule) which can be written to disk efficiently, which in a preferred embodiment is in accordance with the physical location on disk at which each such block will be written. This also generally corresponds to an order which is encountered by a write head during a physical scan of a disk. The disks of a mirrored pair are operated out of phase with each other, so that one will be in read mode while the other is in write mode. Updated blocks are written out to the disk that is in write mode in sorted order, while guaranteed read performance is provided by the other disk that is in read mode. When a batch of updates has been applied to one disk of a mirrored pair, the mirrored pair switch their modes, and the other disk is updated. Preferably the updates are kept in a non-volatile memory, which furthermore advantageously may be made fault-tolerant as well. During recovery a pair of spare alternating mirrored disks is introduced to which new updates are directed, while a background scan process copies data from the surviving disk to the new mirrored pair.

公开(公告)号：DE69028371T2

公开(公告)日：1997-03-13

申请号：DE69028371

申请日：1990-11-08

Applicant: IBM

Inventor： DIAS DANIEL MANUEL ,  IYER BALAKRISHNA RAGHAVENDRA

IPC: G06F15/173 ,  H04L12/43 ,  H04L12/42

公开(公告)号：BR9403306A

公开(公告)日：1995-06-20

申请号：BR9403306

申请日：1994-08-22

Applicant: IBM

Inventor： POLYZOIS CHRISTOS ALKIVIADIS ,  DIAS DANIEL MANUEL

IPC: G06F3/06 ,  G06F11/20 ,  G06F12/00 ,  G06F12/16 ,  G11B27/00 ,  G11C29/00 ,  G11B5/012

Abstract: A fault-tolerant high performance mirrored disk subsystem is described which has an improved disk writing scheme that provides high throughput for random disk writes and at the same time guarantees high performance for disk reads. The subsystem also has an improved recovery mechanism which provides fast recovery in the event that one of the mirrored disks fails and during such recovery provides the same performance as during non-recovery periods. Data blocks or pages which are to be written to disk are temporarily accumulated and sorted (or scheduled) into an order (or schedule) which can be written to disk efficiently, which in a preferred embodiment is in accordance with the physical location on disk at which each such block will be written. This also generally corresponds to an order which is encountered by a write head during a physical scan of a disk. The disks of a mirrored pair are operated out of phase with each other, so that one will be in read mode while the other is in write mode. Updated blocks are written out to the disk that is in write mode in sorted order, while guaranteed read performance is provided by the other disk that is in read mode. When a batch of updates has been applied to one disk of a mirrored pair, the mirrored pair switch their modes, and the other disk is updated. Preferably the updates are kept in a non-volatile memory, which furthermore advantageously may be made fault-tolerant as well. During recovery a pair of spare alternating mirrored disks is introduced to which new updates are directed, while a background scan process copies data from the surviving disk to the new mirrored pair.