Abstract
Memcached is an in-memory key-value distributed caching solution, commonly used by web servers for fast content delivery. Keys with their values are distributed between Mem-cached servers using a consistent hashing technique, resulting in an even distribution (of keys) among the servers. However, as small number of keys are significantly more popular than others (a.k.a., hot keys), even distribution of keys may cause a significantly different request load on the Memcached servers, which, in turn, causes substantial performance degradation. Previous solutions to this problem require complex application level solutions and extra servers. In this paper, we propose MBalancer-A simple L7 load balancing scheme for Memcached that can be seamlessly integrated into Memcached architectures running over Software-Defined Networks (SDN). In a nutshell, MBalancer runs as an SDN application and duplicates the hot keys to many (or all) Memcached servers. The SDN controller updates the SDN switches forwarding tables and uses SDN ready-made load balancing capabilities. Thus, no change is required to Memcached clients or servers. Our analysis shows that with minimal overhead for storing a few extra keys, the number of requests per server is close to balanced (assuming requests for keys follows a Zipf distribution). Moreover, we have implemented MBalancer on a hardware-based OpenFlow switch. As MBalancer offloads requests from bottleneck Memcached servers, our experiments show that it achieves significant throughput boost and latency reduction.
Original language | English |
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Title of host publication | 2017 IFIP Networking Conference, IFIP Networking 2017 and Workshops |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Pages | 1-9 |
Number of pages | 9 |
ISBN (Electronic) | 9783901882944 |
DOIs | |
State | Published - 2 Jul 2017 |
Event | 2017 IFIP Networking Conference and Workshops, IFIP Networking 2017 - Stockholm, Sweden Duration: 12 Jun 2017 → 16 Jun 2017 |
Publication series
Name | 2017 IFIP Networking Conference, IFIP Networking 2017 and Workshops |
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Volume | 2018-January |
Conference
Conference | 2017 IFIP Networking Conference and Workshops, IFIP Networking 2017 |
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Country/Territory | Sweden |
City | Stockholm |
Period | 12/06/17 → 16/06/17 |
Bibliographical note
Publisher Copyright:© 2017 IFIP.