...
Virginia Tech finished the Assessment Plan - Clustering and report our works in this page. The detail step-to-step procedures was documented in Fedora Cluster Installation in AWS.
We applied read-only and read-dominant workloads to replicated Fedora 4 clusters. The write operation do not present as a bottleneck in our experiments. When the number of nodes increases, the maximum read load the cluster can handle also increases linearly. The read latency does not change significantly, although the write latency shows signs of increase when the number of replicated nodes increases. These results should give us high confidence on using replicated Fedora 4 cluster to accommodate higher read workload.
Testing object 1: Verify the load balanced cluster setup using the updated Modeshape and Infinispan configuration.
...
Outcome: When the requests are approximately 525~650 525~550 requests per second, a single Fedora instance is start unable to accept further requests.
...
Testing object 5: Exam if the n-node (n >= 2) cluster handles n times as much requests as a single instance.
Outcome: We conducted load test on single, 2 nodes cluster, 3 nodes cluster, and 4 nodes cluster. Below table shows number of requests which server can response all requests completely.
| Single | Cluster (n=2) | Cluster (n=3) | Cluster (n=4) | |
|---|---|---|---|---|
| reqs/sec | 525 | 650 | 725 | 810 |
Testing object 6: n-JMeter (n=2) clients to send requests in different region/availability zone and measure the response time.
...
Testing object 7: Simulate real world case, 95% read requests and 5% write requests.
Outcome: To simulate real world case, we use a JMeter to send in a read/write(create/delete) ratio (95%/5%) per second and measure the average Fedora 4 cluster (3 nodes) response time.
| Read | Write | Action | Node | |
|---|---|---|---|---|
| Only Read reqs | 5ms | 4 | ||
| Only Write reqs | 13ms | Create | 4 | |
| Only Write reqs | 190ms | Delete | 4 | |
| Only Read reqs | 5ms | 3 | ||
| Only Write reqs | 21ms | Create | 3 | |
| Only Write reqs | 66ms | Delete | 3 | |
| Only Read reqs | 4ms | 1 | ||
| Only Write reqs | 13ms | Create | 1 | |
| Only Write reqs | 63ms | Delete | 1 |
| Read | Write | Action | Node | |
|---|---|---|---|---|
| R-reqs/W-reqs (95%/5%) | 4ms | 14ms | Create | 4 |
| R-reqs/W-reqs (95%/5%) | 5ms | 216ms | Delete | 4 |
| R-reqs/W-reqs (95%/5%) | 7ms | 29ms | Create | 3 |
| R-reqs/W-reqs (95%/5%) | 5ms | 61ms | Delete | 3 |
| R-reqs/W-reqs (95%/5%) | 4ms | 15ms | Create | 1 |
| R-reqs/W-reqs (95%/5%) | 4ms | 63ms | Delete | 1 |
Below table shows number of requests which server can response all requests completely under pressure test. The read requests which server can handle reduced a little, however the write requests remains the same.
| Single | Cluster (n=2) | Cluster (n=3) | Cluster (n=4) | |
|---|---|---|---|---|
| RW-reqs/sec | 480 | 590 | 680 | 780 |
This figure shows the difference between read-only and read-write. Blue line shows read-only and green line shows read-write.
