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Member Stickness on Hot Page in Shared Resource System

IP.com Disclosure Number: IPCOM000237576D
Publication Date: 2014-Jun-25
Document File: 6 page(s) / 106K

Publishing Venue

The IP.com Prior Art Database

Abstract

In a resource shared system, several members share disk - pages are shared between multiple members. Sharing also means contention, those pages those are modified by multiple members frequently become "hot". For example, in the high concurrent OLAP workload, new rows are added to a table, then the last page becomes very hot since rows will be inserted into this page. this article will give a idea that, to allocate new page for each member by storing the member id in the page header. Then each member has its own/private page for INSERT - adding new records, INSERT contention is avoided. But the pages/rows are still shared by all the members for read and update.

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Page 01 of 6

Member Stickness on Hot Page in Shared Resource System

In a resource shared system, several members share disk - pages are shared between multiple members. Sharing also means contention, those pages those are modified by multiple members frequently become "hot". For example, in the high concurrent OLAP workload, new rows are added to a table, then the last page becomes very hot since rows will be inserted into this page.

Hot page contention may become a critical performance problem in high concurrent OLTP. In a simulation test(Refer to following graph), hot page contention causes a catastrophic throughput drop in performance.

Key question

Key question:


Key Idea Key Idea:

:Allocate new page for each member by storing the member id in the page header. Then each member has its own/private page for

:Why can't each member have some private pages to avoid contention for special operator, e.g., for INSERT?

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Page 02 of 6

INSERT - adding new records, INSERT contention is avoided. But the pages/rows are still shared by all the members for read and update.

Existing method to serialize page modification

To make data consistency, modification on the same page should be serialized between multiple members. Each member needs to hold a page-exclusive(P-X) lock when modifying the page. So when member B wants to modify a page and the page is P-X locked by member A, A should reclaim the P-X lock and several things should be done in this reclaim process which may impact the performance.

For example, the hot page is hold by member 1 for modification, and P-X lock is hold. Then if member 2 want to add new rows to the same pages, it need to request a P-X lock.

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Here the steps :

1. Member 2 ask coo...