On Maximizing iSCSI Throughput Using Multiple Connections with Automatic Parallelism Tuning

Abstract

In this paper, we propose an iSCSI-APT (iSCSI with Automatic Parallelism Tuning) that maximizes iSCSI throughput in long-fat networks. In recent years, as a protocol for building SANs (Storage Area Networks), iSCSI has been attracting attention for its low cost and high compatibility with existing networking infrastructure. However, it has been known that iSCSI throughput degrades in a long-fat network. iSCSI supports a feature called multiple connections, which allows data delivery over multiple TCP connections in a single session. However, for effective utilization of the multiple connections feature, the number of multiple connections must be appropriately configured according to the network status. In this paper, we propose the iSCSI-APT that automatically adjusts the number of multiple connections according to the network status. Through experiments using our iSCSI-APT implementation, we demonstrate that iSCSI-APT operates quite effectively regardless of the network delay.

Development of an ATCA based data acquisition system for high speed, direct detection X-ray pixel sensors

“…To interface the CIN with the RAID and other external networks, a protocol bridge is used to translate UDP to Internet Small Computer System Interface (iSCSI) and Transmission Control Protocol (TCP) respectively [4]. On the prototype system, the protocol bridge node was implemented in software on a processor blade in the expansion node slot of the ATCA crate.…”

On Maximizing IP-SAN Throughput over TCP Connections with Automatic Parallelism Tuning for Long-Fat Networks

“…Several solutions for preventing degradation of the IP-SAN performance in a long-fat network have been proposed [4,6,15]. For instance, to prevent throughput degradation of iSCSI protocol, solutions utilizing multiple links [15] or parallel TCP connections [4] have been proposed.…”

“…Several solutions for improving the throughput of IP-SAN protocols have been proposed [4,6,15]. There exist several factors affecting the performance of IP-SAN protocols in a long-fat network.…”

“…However, for effective use of parallel TCP connections, the parallelism (i.e., the number of multiple TCP connections established) must be appropriately chosen according to network status [5]. We have proposed APT (Automatic Parallelism Tuning) mechanism for improving the performance of GridFTP [1] and iSCSI [13] , which automatically adjusts the number of parallel TCP connections based on the measured network status [4,5].…”

“…BDL-APT parallelizes data transfer by dividing aggregated read/write requests into multiple chunks, and then transfering a chunk of requests on every IP-SAN session in parallel. BDL-APT automatically optimizes the number of IP-SAN sessions based on the measured network status using our APT mechanism [4,5].…”