[JAVA-1567] Calculate round trip time using exponentially weighted average Created: 19/Nov/14 Updated: 31/Mar/15 Resolved: 21/Nov/14 |
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| Status: | Closed |
| Project: | Java Driver |
| Component/s: | Cluster Management |
| Affects Version/s: | None |
| Fix Version/s: | 3.0.0 |
| Type: | New Feature | Priority: | Major - P3 |
| Reporter: | Jeffrey Yemin | Assignee: | Jeffrey Yemin |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Description |
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If there have been no RTT measurements for a server (e.g. the first ismaster command after the server becomes available), the average RTT MUST be set equal to the first RTT measurement. After the first measurement, average RTT MUST be computed using an exponentially-weighted moving average formula, with a weighting factor (alpha) of 0.2. If the prior average is denoted old_rtt, then the new average (new_rtt) is computed from a new RTT measurement
A weighting factor of 0.2 was chosen to put about 85% of the weight of the average RTT on the 9 most recent observations. |
| Comments |
| Comment by Jeffrey Yemin [ 31/Mar/15 ] |
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Closing all resolved 3.0.0 issues, as 3.0.0 has been tagged and released. |
| Comment by Githook User [ 30/Jan/15 ] |
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Author: {u'username': u'jyemin', u'name': u'Jeff Yemin', u'email': u'jeff.yemin@10gen.com'}Message: Calculate round trip time as an exponentially weighted moving average, using a value of 0.2 for the weighting factor. |
| Comment by Githook User [ 21/Nov/14 ] |
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Author: {u'username': u'jyemin', u'name': u'Jeff Yemin', u'email': u'jeff.yemin@10gen.com'}Message: Calculate round trip time as an exponentially weighted moving average, using a value of 0.2 for the weighting factor. |