System and method for expediting transfer of sectioned audit files from a primary host to a secondary host

• US 6,408,310 B1
• Filed: 10/08/1999
• Issued: 06/18/2002
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Hart, Donald Ralph
• Primary Examiner(s): Alam, Hosain T.
• Application Number:
  US09/415,274
• Time in Patent Office: 984 Days
• Field of Search: 707/201-204, 707/10, 707/100-102, 709/226, 709/237-239, 709/248, 714/2, 714/4, 714/6, 714/8, 714/10, 714/12, 714/15-16, 714/19-20, 714/33
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2066 Optimisation of the communication load
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

In order to correlate or synchronize the database of a source primary host with the backup database of a remote secondary host, the present method operates to speed up the transfer of audit blocks from primary host to secondary host when an out-of-sync signal indicates the secondary host audit blocks are not on a par with the primary host audit blocks. A Catchup process utilizes multiple buffers of audit blocks at the primary host which can then be asynchronously transferred, by a sequence of Catchup tasks, on a parallel concurrent operation, over to physical files of said secondary host.

Claims

1. A Catchup process providing a method for increasing the transfer rate of audit blocks from a primary host to a secondary host when a lack of synchronism in audit data is indicated, said method comprising the steps of:

(a) initiating, via a library support unit, the start of a Catchup mode for expediting transfer of packets of audit blocks;

(b) opening up, via a Catchup Task unit, specialized port files for connection from said primary host to said secondary host;

(c) signaling, by said Catchup Task unit, to said library support unit to start up a Catchup server unit in said primary host;

(d) asynchronously receiving, by said secondary host, of multiple packets of said audit blocks concurrently along parallel paths;

(e) placing said received multiple packets into physical files at said secondary host.

2. The method of claim 1, wherein steps (c) includes the steps of:

(c1) reading out, at said primary host, packets of multiple audit blocks in the same order they were written into said primary host;

(c2) placing each of said packets of multiple audit blocks into separate individual buffers of parallel buffers in said primary host.

3. The method of claim 1 wherein step (e) includes the step of:

(e1) writing each of said multiple audit blocks asynchronously along multiple parallel paths into physical files of said secondary host.

4. A method for asynchronous parallel transfer of sectioned audit files received at a secondary remote host (30) from a primary source host (10) when a condition of non-synchronization is indicated, said method comprising the steps of:

(a) initiating, by a Database Support Library means, of a sequential set of Catchup operations;

(b) opening special Catchup port files to enable sectioned audit files from said primary source host to deposit said sectional audit files at said secondary remote host;

(c) utilizing said sequential set of Catchup operations to concurrently and asynchronously write said multiple sets of sectioned audit files to said remote host.

5. A system for expediting transfer of audit blocks of sectioned audit files read into parallel buffers at a primary host over to sectioned audit files at a secondary host when a condition of non-synchronization between said primary host and secondary host is indicated, said system comprising:

(a) Catchup server task means for reading audit blocks from a sectioned audit file and placing them in multiple buffers, each buffer of which will hold a group of blocks from a corresponding audit file section of said primary source audit file;

(b) library support means for conveying each buffer section of said primary audit trail into multiple sections of secondary remote audit files;

(c) multiple sets of Catchup programs operating in concurrent sequences onto said remote sets of sectioned audit files for expediting their transfer onto a secondary database.

6. In a network for transferring audit files from a primary host to a secondary host when a lack of synchronism occurs between said primary host and said secondary host, a Catchup system for expediting the transfer of sectioned audit files from said primary host to said secondary host comprising:

(a) library support means for initiating a first Catchup task to expedite the delivery of a first audit file section onto said remote database;

(b) means to open up the port files of all Catchup tasks to enable a steady flow of sectioned audit files from said primary host onto said secondary host;

(c) Catchup server means for initiating a sequence of port write operations, each operation of which will transfer a sectioned audit file of said primary host onto said database of said secondary host in a parallel concurrent set of operations.