CAPACITY PLANNING FOR DATABASE REPLICATION LATENCY
A system, methods, and apparatus are provided for performing capacity planning within a system that experiences high volumes of data having high velocity and high variability. Based on historical traffic, a forecast is generated for one or more relatively coarse time periods (e.g., weeks, days), and is decomposed to yield finer-grained forecasts (e.g., for hours, minutes) by applying a distribution index also generated from historical traffic. Estimated replication latency for the forecast period can be calculated from the traffic forecast and an expected level of replication capacity. Further, a required amount of replication capacity can be determined based on a traffic forecast and a maximum replication latency permitted by a service level agreement (SLA) of an event consumer. In addition, replication headroom can be computed, to identify a maximum level of traffic that can be sustained without violating an SLA and/or a date/time at which a violation may occur.
1 . A method comprising:
receiving electronic events generated during operation of an online service;
replicating the received events for consumption by components of a computer system that hosts the online service;
based on electronic event traffic received during multiple first time periods of a first duration during a historical period of a second duration, generating a distribution index reflecting, for each first time period, a portion of event traffic received during the historical period that was received during the first time period;
based on electronic event traffic received during multiple second time periods of a second duration, forecasting event traffic for one or more future time periods of the second duration; and
applying the distribution index to distribute event traffic forecasted for the one or more future time periods of the second duration among a plurality of future time periods of the first duration.
2 . The method of claim 1 , further comprising:
for each of the plurality of future time periods, estimating a replication latency to be exhibited during replication of events forecasted to be received during the future time period.
3 . The method of claim 2 , wherein the replication latency estimated for a given future time period is estimated by:
comparing a forecasted rate of receipt of electronic events during the given future time period with a capacity of the computer system for replicating electronic events during the given future time period; and
adjusting an estimated replication latency accumulated prior to the given future time period based on the comparison.
4 . The method of claim 2 , wherein the replication latency estimated for a given future time period is estimated based on one of:
a current replication capacity identifying a number of electronic events that can currently be replicated in a unit of time; and
a forecasted replication capacity identifying a number of electronic events that can be replicated in the given future time period.
5 . The method of claim 2 , further comprising:
for each of the plurality of future time periods, determining a required replication capacity for replicating the events forecasted to be received during the future time period without violating a replication latency metric of a service level agreement.
6 . The method of claim 5 , wherein the required replication capacity is determined by applying a binary search among candidate replication capacities.
7 . The method of claim 5 , further comprising:
for each of the plurality of future time periods, estimating replication headroom comprising one or more of:
a factor by which the event traffic forecasted for the future time period can be scaled up without violating the replication latency metric; and
a period of time until the replication latency metric is likely to be violated.
8 . The method of claim 1 , wherein:
the first duration comprises one hour; and
the second duration comprises one week.
9 . A system, comprising:
at least one processor;
a replication module comprising a first non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the system to:
receive electronic events generated during operation of an online service hosted by the system; and
replicate the received events for consumption by components of the system; and
a traffic forecast module comprising a second non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the system to:
based on electronic event traffic received during multiple first time periods of a first duration during a historical period of a second duration, generate a distribution index reflecting, for each first time period, a portion of event traffic received during the historical period that was received during the first time period;
based on electronic event traffic received during multiple second time periods of a second duration, forecast event traffic for one or more future time periods of the second duration; and
apply the distribution index to distribute event traffic forecasted for the one or more future time periods of the second duration among a plurality of future time periods of the first duration.
10 . The system of claim 9 , further comprising:
a replication latency module comprising a third non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the system to:
for each of the plurality of future time periods, estimate a replication latency to be exhibited during replication of events forecasted to be received during the future time period.
11 . The system of claim 10 , wherein the replication latency estimated for a given future time period is estimated by:
comparing a forecasted rate of receipt of electronic events during the given future time period with a capacity of the computer system for replicating electronic events during the given future time period; and
adjusting an estimated replication latency accumulated prior to the given future time period based on the comparison.
12 . The system of claim 10 , further comprising:
a replication capacity module comprising a fourth non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the system to:
for each of the plurality of future time periods, determine a required replication capacity for replicating the events forecasted to be received during the future time period without violating a replication latency metric of a service level agreement.
13 . The system of claim 12 , further comprising:
a replication headroom module comprising a fifth non-transitory computer readable medium storing instructions that, when executed by the at least one processor, cause the system to:
for each of the plurality of future time periods, estimate replication headroom comprising one or more of:
a factor by which the event traffic forecasted for the future time period can be scaled up without violating the replication latency metric; and
a period of time until the replication latency metric is likely to be violated.
14 . The system of claim 9 , wherein:
the first duration comprises one hour; and
the second duration comprises one week.
15 . An apparatus, comprising:
one or more processors;
logic comprising instructions that, when executed by the one or more processors, cause the apparatus to:
receive electronic events generated during operation of an online service hosted by the apparatus;
replicate the received events for consumption by components of the apparatus;
based on electronic event traffic received during multiple first time periods of a first duration during a historical period of a second duration, generate a distribution index reflecting, for each first time period, a portion of event traffic received during the historical period that was received during the first time period;
based on electronic event traffic received during multiple second time periods of a second duration, forecast event traffic for one or more future time periods of the second duration; and
apply the distribution index to distribute event traffic forecasted for the one or more future time periods of the second duration among a plurality of future time periods of the first duration.
16 . The apparatus of claim 15 , wherein the logic further comprises instructions that, when executed by the one or more processors, cause the apparatus to:
for each of the plurality of future time periods, estimate a replication latency to be exhibited during replication of events forecasted to be received during the future time period;
for each of the plurality of future time periods, determine a required replication capacity for replicating the events forecasted to be received during the future time period without violating a replication latency metric of a service level agreement; and
for each of the plurality of future time periods, estimate replication headroom comprising one or more of:
a factor by which the event traffic forecasted for the future time period can be scaled up without violating the replication latency metric; and
a period of time until the replication latency metric is likely to be violated.
17 . The apparatus of claim 16 , wherein:
the first duration comprises one hour; and
the second duration comprises one week.