公开(公告)号：CA2761553C

公开(公告)日：2019-03-05

申请号：CA2761553

申请日：2011-12-09

Applicant: IBM CANADA LTD IBM CANADA LIMITEE

Inventor： SACHEDINA AAMER ,  HURAS MATTHEW A

IPC: G06F12/00 ,  G06F12/0866

Abstract: An illustrative embodiment of a computer-implemented process for logical buffer pool extension identifies a page in a memory for eviction, analyzes characteristics of the page to form a differentiated page, wherein the characteristics of the page comprise descriptors including a workload type, a page weight, a page type, frequency of access and timing of most recent access and identifies a target location for the differentiated page from a set of locations including a fastcache storage and a hard disk storage to form an identified target location. The process further selects an eviction operation from a set of eviction operations using the characteristics of the differentiated page and the identified target location and writes the differentiated page to the identified target location using the selected eviction operation wherein the differentiated page is written only to the fastcache storage.

公开(公告)号：CA2719673A1

公开(公告)日：2011-01-18

申请号：CA2719673

申请日：2010-11-05

Applicant: IBM CANADA

Inventor： BAE MYUNG M ,  BUCKLER ANDREW D ,  CHAN YUE FONG Y ,  GARCIA-ARELLANO CHRISTIAN M ,  HURAS MATTHEW A ,  MUELLER MARKUS ,  SACHEDINA AAMER ,  SCHMUCK FRANK B ,  VOLOBUEV YURI

IPC: G06F11/07 ,  G06F15/16

Abstract: An illustrative embodiment of a computer-implemented process for fencing shared cluster resources in event of a possible split-brain, identifies a failing resource of a node within a set of shared resources to form an identified failing resource, fences a subset of the set of shared resources to form a winning subset of shared resources and prevents the identified failing resource from communicating with the winning subset of shared resources using a white list maintained at each database system of the winning subset of shared resources. The computer-implemented process further determines whether the identified failing resource has been cleared to form a cleared failing resource and responsive to a determination that the identified failing resource has been cleared, rejoins the cleared failing resource with the winning subset of the set of shared resources absent a re-boot of the cleared failing resource.

公开(公告)号：CA2384185A1

公开(公告)日：2003-10-29

申请号：CA2384185

申请日：2002-04-29

Applicant: IBM CANADA

Inventor： ROMANUFA KERILEY K ,  SACHEDINA AAMER ,  HURAS MATTHEW A

IPC: G06F12/08 ,  G06F12/00 ,  G06F17/30 ,  G06F12/02 ,  G06F9/44

Abstract: A hash table is provided in which identifying properties of the data items pointed to by the hash table are selected and are included within the hash table buckets. The properties recorded in the buckets are able to be stored in a cache for the hash table and are used to located data items pointed to by the hash table. The hash table has bucket groups defining a second level hash table. The bucket groups are used to permit resizing of the hash table. Each bucket group has a latch so that that exclusive access for the resizing operation is obtainable on a group by group basis.

公开(公告)号：CA2353017A1

公开(公告)日：2003-01-12

申请号：CA2353017

申请日：2001-07-12

Applicant: IBM CANADA

Inventor： LI JOHN ,  HURAS MATTHEW A ,  SACHEDINA AAMER ,  ROMANUFA KERILEY K ,  SCHLAMB KELLY W ,  ZHENG ROGER L

IPC: G06F3/06 ,  G06F11/14 ,  G06F11/20 ,  G06F17/30 ,  G11B27/10 ,  G11B25/04

公开(公告)号：CA2433254A1

公开(公告)日：2004-12-25

申请号：CA2433254

申请日：2003-06-25

Applicant: IBM CANADA

Inventor： HURAS MATTHEW A ,  SACHEDINA AAMER ,  ROMANUFA KERILEY K

IPC: G06F12/02 ,  G06F12/08 ,  G06F13/38 ,  G06F17/30 ,  G11C7/10

Abstract: A system and method for warm shutdown and restart of a buffer pool is provided. The buffer content including pages and control structures associated with these pages i s partitioned into blocks and each block is saved to disk as a sequential file. The size of eac h block may be selected to provide the optimal I/O (input/output) efficiency during buffer pool shutdown and restart operations. Blocks can be saved simultaneously using a number of writer threads. During restart of the buffer pool, the control information is read from the disk an d restored to the buffer pool using reader threads. The buffer pool may be made available for references to pages while reader threads are enabled to read the saved information by blocks to facilitate a more rapid restoration of information in the buffer pool. Allocation of portions of the buffer pool for restoring pages may be performed while the buffer pool is available for references to hasten availability.

公开(公告)号：CA2306969A1

公开(公告)日：2001-10-28

申请号：CA2306969

申请日：2000-04-28

Applicant: IBM CANADA

Inventor： HURAS MATTHEW A ,  ROMANUFA KERILEY K ,  SACHEDINA AAMER

IPC: G06F9/50 ,  G06F9/46 ,  G06F9/48

Abstract: A computer system dynamically scales back latch requests for system resource s. Tasks seeking access to system resources each dynamically determine the probability that t he task will gain access to the latch relating to a given system resource. Where the task estimates that its probability is below a defined threshold, the task will suspend itself for a defined sleep time. The task dynamically adjusts the length of the sleep time based on the number of times the task enters the suspended state and on the relative changes in the estimated probability that the task will gain access to the resource.

公开(公告)号：CA2761553A1

公开(公告)日：2013-06-09

申请号：CA2761553

申请日：2011-12-09

Applicant: IBM CANADA

Inventor： SACHEDINA AAMER ,  HURAS MATTHEW A

IPC: G06F12/00 ,  G06F12/0866

Abstract: An illustrative embodiment of a computer-implemented process for logical buffer pool extension identifies a page in a memory for eviction, analyzes characteristics of the page to form a differentiated page, wherein the characteristics of the page comprise descriptors including a workload type, a page weight, a page type, frequency of access and timing of most recent access and identifies a target location for the differentiated page from a set of locations including a fastcache storage and a hard disk storage to form an identified target location. The process further selects an eviction operation from a set of eviction operations using the characteristics of the differentiated page and the identified target location and writes the differentiated page to the identified target location using the selected eviction operation wherein the differentiated page is written only to the fastcache storage.

公开(公告)号：CA2422161C

公开(公告)日：2009-10-06

申请号：CA2422161

申请日：2003-03-14

Applicant: IBM CANADA

Inventor： WINER MICHAEL J ,  LAU LEO TAT MAN ,  BERKS ROBERT T ,  ROMANUFA KERILEY K ,  FLASZA MIROSLAW A ,  HURAS MATTHEW A ,  SACHEDINA AAMER

IPC: G06F17/30 ,  G06F7/00

Abstract: The use of a centralized version table allows for efficient object switching . Rather than synchronizing all database agents to recognize a newly created file as containing the most recent version of a given object, database agents requiring access to t he given object need only consult the centralized version table to learn file identity information. That is, the database agents consult the centralized version table to determine which of the files associated with a given object contain the most recent version of the given object. Mechanisms associated with the use of the centralized version table also provide for efficient recovery from a failure that has occurred during an object switchi ng transaction.

公开(公告)号：CA2438366A1

公开(公告)日：2005-02-26

申请号：CA2438366

申请日：2003-08-26

Applicant: IBM CANADA

Inventor： ROMANUFA KERILEY K ,  SACHEDINA AAMER ,  HURAS MATTHEW A

IPC: G06F17/30 ,  H04L12/16

Abstract: For an information retrieval system coupled to a buffer pool maintaining a plurality of pages of recently accessed information for subsequent re-access , there is provided a method of starting the buffer pool. The method facilitates a quicker start to the buffer pool by deferring allocation of page storing portions, for example, until they ar e needed. The method comprises making the buffer pool available for storing pages while deferring allocation of a page storing portion of the buffer pool; and allocating the page storing portion of the buffer pool in response to a demand to store pages to the buffer pool . The method may be used to re-start a buffer pool with pages stored to a memory coupled to t he information retrieval system where the pages where stored upon a buffer pool shutdown. Further, buffer pool readers or prefetchers may be configured to read pages for storing to t he buffer pool and allocate the page storing portions of the buffer pool in response to instructions to read particular pages.

公开(公告)号：CA2422161A1

公开(公告)日：2004-09-14

申请号：CA2422161

申请日：2003-03-14

Applicant: IBM CANADA

Inventor： ROMANUFA KERILEY K ,  HURAS MATTHEW A ,  WINER MICHAEL J ,  FLASZA MIROSLAW A ,  BERKS ROBERT T ,  LAU LEO TAT MAN ,  SACHEDINA AAMER

IPC: G06F7/00 ,  G06F17/30

Abstract: The use of a centralized version table allows for efficient object switching. Rather than synchronizing all database agents to recognize a newly created file as containing the most recent version of a given object, database agents requiring access to the given object need only consult the centralized version table to learn file identity information. That is, the database agents consult the centralized version table to determine which of the files associated with a given object contain the most recent version of the given object. Mechanisms associated with the use of the centralized version table also provide for efficient recovery from a failure that has occurred during an object switching transaction.