Database Reference
In-Depth Information
different configurations of geographic locations by running
ping
6
command every
second for a 20-minute period. The results suggest an average of 16, 21, and 173 ms
for the 1/2 round-trip time for the same zone in Figs.
6.8
and
6.11
, different zones
in Figs.
6.9
and
6.12
, and different regions in Figs.
6.10
and
6.13
, respectively.
However, the trends of the average relative replication delay can usually go up to
two to four orders of magnitude as shown from Figs.
6.8
-
6.10
, or one to three orders
of magnitude as shown in Figs.
6.11
-
6.13
. Therefore, it could be suggested that
the geographic replication would be applicable in the cloud as long as workload
characteristics can be well managed, such as having a smart load balancer which is
able to balance the operations based on the estimated processing time.
6.4
Discussion
In practice, there are different approaches for deploying data-intensive applications
in cloud platforms. In this chapter, the study is focused on the
virtualized database
servers
approach where the resources of the database tiers are migrated to virtual
machines in the public cloud. The behavior of the master-slave database replication
strategy on Amazon EC2 has been experimentally evaluated using the Cloudstone
benchmark and MySQL databases. The experiments involved two configurations
of different workload read/write ratios, namely 50/50 and 80/20, and different
configuration of the geographical locations of the virtualized database replica
servers.
The results of the study show that the performance variation of the dynamically
allocated virtual machines is an inevitable issue that needs to be considered when
deploying database in the cloud. Clearly, it affects the end-to-end throughput. Addi-
tionally, different configurations of geographic locations can also noticeably affect
the end-to-end throughput. For most cases, as the number of workload increases,
the replication delay increases. However, as the number of slaves increases, the
replication delay is found decreases. The effect of the configurations of geographic
location is not as significant as increasing workloads in affecting the replication
delay.
