Browse Prior Art Database

Improved Caching of Net.Commerce Pages

IP.com Disclosure Number: IPCOM000013412D
Original Publication Date: 2001-May-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Abstract

A program is disclosed that improves the number of web pages that can be cached by Net.Commerce on OS/390. Instead of only caching URLs that are less than 250 characters in length, the new algorithm allows URLs up to 4050 characters long to be cached. Many Net.Commerce URLs can easily exceed 250 characters, and these web pages would not be cached. Now these web pages can be cached, dramatically improving Net.Commerce performance. More about the problem... Net.Commerce Version 3.1.2 on OS/390 caches generated web pages in DB2. The method used requires the URL of the web page to be used as a key into a DB2 table. Since DB2 has a restriction of 250 bytes for keys, Net.Commerce could only cache pages whole URL length did not exceed this limit. While performance testing customer websites we found that many routinely had URLs longer than 250. These pages would not be cached by Net.Commerce, resulting in a severe performance degradation. Our solution was to redesign the caching algorithm to allow pages with URLs up to 4050 bytes to be cached. This is the new caching algorithm: When storing a page in cache:

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Improved Caching of Net.Commerce Pages

  A program is disclosed that improves the number of web pages that can be cached by Net.Commerce on OS/390. Instead of only caching URLs that are less than 250 characters in length, the new algorithm allows URLs up to 4050 characters long to be cached. Many Net.Commerce URLs can easily exceed 250 characters, and these web pages would not be cached. Now these web pages can be cached, dramatically improving Net.Commerce performance.

More about the problem... Net.Commerce Version 3.1.2 on OS/390 caches generated web pages in DB2. The method used requires the URL of the web page to be used as a key into a DB2 table. Since DB2 has a restriction of 250 bytes for keys, Net.Commerce could only cache pages whole URL length did not exceed this limit. While performance testing customer websites we found that many routinely had URLs longer than 250. These pages would not be cached by Net.Commerce, resulting in a severe performance degradation.

Our solution was to redesign the caching algorithm to allow pages with URLs up to 4050 bytes to be cached. This is the new caching algorithm:

When storing a page in cache:

Hash the URL of the page to 4 bytes, using the POSIX.2 standard checksum

algorithm. This algorithm is already used in the OS/390 Unix System Services "cksum -p" command. Store the hashed URL in the database table's key field, and store the full URL in

another field of the table. Disregard any errors if the key matches an existing...