4 ms·

Help me out, who needs this and what are some usecases for such high accuracy/resolution. Genuinely curious.

deleted 3y ago
[deleted]
jitl 3y ago
It’s helpful in coordinating distributed systems, like how Google uses “TrueTime” in Spanner to ensure external consistency: https://cloud.google.com/spanner/docs/true-time-external-consistency#1 https://cloud.google.com/spanner/docs/true-time-external-con... Garden variety NTP time / system time I wouldn’t trust as an oracle for distributed systems but this kind of high precision time is probably suitable for that use.
coldbrewed 3y ago
I can't comment on infrastructure in AWS, but I worked at an observatory for a hot minute when they used Precision Time Protocol (PTP). Their scheme was to record telemetry from all aspects of the observatory -- hardware state, environmental and atmospheric conditions, software and system state, commands, etc. The intent was to build a hyper-precise set of telemetry that could be used to retroactively reprocess old imaging from the observatory as more imaging and telemetry was generated and it would be easier to do that with more accurate timing. With this level of resolution, multiple observatories can more effectively share and synthesize data; if you know the state of two observatories down to the tens or hundreds of nanoseconds you can do more advanced work with synthetic aperture imaging. Beyond astronomy my other guess is that PTP or similar tech might be used for high frequency trading; it might also be useful for creating distributed systems; Google's Cloud Spanner uses TrueTime which IIRC is a proprietary equivalent of PTP.
- bestouff 3y ago
  PTP is nearly always proprietary. It's very configurable and has to be configured to work. So there are many sets of settings called "profiles", defined by various industries for their own needs. They're not completely interoperable, but all have in common a high precision. So you could say PTP is a kit to build timesync protocols.
  - maxnoe 3y ago
    Since this comes from a physics context, it's most likely talking about the white rabbit implementation of ptp, which is open source and open hardware: https://white-rabbit.web.cern.ch/ https://white-rabbit.web.cern.ch/
    - bradknowles 3y ago
      PTP is not scalable. It can work fine on smaller networks, but becomes more and more troublesome as the networks get larger and larger.
- deleted 3y ago
  [deleted]
shikhar 3y ago
It can be used to optimize consensus and transaction protocols. Consensus example - check out Nezha (https://arxiv.org/abs/2206.03285 https://arxiv.org/abs/2206.03285), they came up with an interesting 'Deadline Ordered Multicast' (DOM) primitive > DOM follows Liskov's suggestion of "depending on clock synchronization for performance but not for correctness" Transactions example - look no further than DynamoDB, https://muratbuffalo.blogspot.com/2023/08/distributed-transactions-at-scale-in.html https://muratbuffalo.blogspot.com/2023/08/distributed-transa... > In order to relieve your anxiety before you read further, no, correctness does not depend on timestamps, clock synchronization only helps to improve performance, as more accurate clocks result in more successful transactions and a serialization order that complies with real time.
jmgpeeter 3y ago
HFT crypto trading.
cltby 3y ago
High frequency trading (measuring latency, inferring event ordering, etc). Since most crypto derivatives trading takes place at ap-northeast-1, it feels like AWS is orienting this release towards financial markets customers.

deleted 3y ago

[deleted]

jitl 3y ago

It’s helpful in coordinating distributed systems, like how Google uses “TrueTime” in Spanner to ensure external consistency: https://cloud.google.com/spanner/docs/true-time-external-consistency#1 https://cloud.google.com/spanner/docs/true-time-external-con... Garden variety NTP time / system time I wouldn’t trust as an oracle for distributed systems but this kind of high precision time is probably suitable for that use.

coldbrewed 3y ago

I can't comment on infrastructure in AWS, but I worked at an observatory for a hot minute when they used Precision Time Protocol (PTP). Their scheme was to record telemetry from all aspects of the observatory -- hardware state, environmental and atmospheric conditions, software and system state, commands, etc. The intent was to build a hyper-precise set of telemetry that could be used to retroactively reprocess old imaging from the observatory as more imaging and telemetry was generated and it would be easier to do that with more accurate timing. With this level of resolution, multiple observatories can more effectively share and synthesize data; if you know the state of two observatories down to the tens or hundreds of nanoseconds you can do more advanced work with synthetic aperture imaging. Beyond astronomy my other guess is that PTP or similar tech might be used for high frequency trading; it might also be useful for creating distributed systems; Google's Cloud Spanner uses TrueTime which IIRC is a proprietary equivalent of PTP.

bestouff 3y ago
PTP is nearly always proprietary. It's very configurable and has to be configured to work. So there are many sets of settings called "profiles", defined by various industries for their own needs. They're not completely interoperable, but all have in common a high precision. So you could say PTP is a kit to build timesync protocols.
- maxnoe 3y ago
  Since this comes from a physics context, it's most likely talking about the white rabbit implementation of ptp, which is open source and open hardware: https://white-rabbit.web.cern.ch/ https://white-rabbit.web.cern.ch/
  - bradknowles 3y ago
    PTP is not scalable. It can work fine on smaller networks, but becomes more and more troublesome as the networks get larger and larger.
deleted 3y ago
[deleted]

shikhar 3y ago

It can be used to optimize consensus and transaction protocols. Consensus example - check out Nezha (https://arxiv.org/abs/2206.03285 https://arxiv.org/abs/2206.03285), they came up with an interesting 'Deadline Ordered Multicast' (DOM) primitive > DOM follows Liskov's suggestion of "depending on clock synchronization for performance but not for correctness" Transactions example - look no further than DynamoDB, https://muratbuffalo.blogspot.com/2023/08/distributed-transactions-at-scale-in.html https://muratbuffalo.blogspot.com/2023/08/distributed-transa... > In order to relieve your anxiety before you read further, no, correctness does not depend on timestamps, clock synchronization only helps to improve performance, as more accurate clocks result in more successful transactions and a serialization order that complies with real time.

jmgpeeter 3y ago

HFT crypto trading.

cltby 3y ago

High frequency trading (measuring latency, inferring event ordering, etc). Since most crypto derivatives trading takes place at ap-northeast-1, it feels like AWS is orienting this release towards financial markets customers.