AWS re:Invent 2018: Amazon DynamoDB Under the Hood: How We Built a Hyper-Scale Database (DAT321)

[@dimkir100]

This one is an awesome talk. Jaso goes through important innards of DynamoDB, including secondary indexes, throttling, burst capacity, accumulating read capacity, adaptive capacity, etc.

[@ahmxtb]

I've read both Dynamo 2007 and DynamoDB 2022 papers and this is a great summary. Thanks.

[@awssupport]

Glad you enjoyed it, Ahmet! 😃 ^KR

[@CAMorales82]

0:00 Intro 2:39 Agenda - GetItem/PutItem - Auto Scaling - Backup Restore - Streams - Global Tables 3:04 GetItem/PutItem - Request Router - Paxos - Partition Metadata System - Tables (hashing, partitioning) - Eventual Consistency - Storage Nodes (B-tree, Replication Log) - System Management (Auto Admin, Partition Repair) - Secondary Index (Log Propagator) - Provisioning Table Capacity - Adaptive Capacity 28:48 Auto Scaling 33:54 Backup Restore - Point in Time - On-demand backup 41:43 Streams 44:45 Global Tables

[@galeop]

Key takeaways: - storage nodes acknowledge a WRITE (on a partition) back to the request router if 2 out of the 3 storage nodes for the affected partition successfully completed the WRITE. So when you perform an "eventually consistent READ", the odds to get a strongly consistent result are 2/3. -The 3 storage nodes of a partition decide between themselves which one will be the partition leader. - Leader nodes store the partition data into a B-tree index, and they also maintain a "replication log" (a kind of TX log).

[@shawapratim]

Amazing. Just what I needed. Thank you for making this available here.

[@saumilkapadia88]

very nicely described. kept on watching and watching. came back to this video multiple times when i understood more and more.

[@rahulat85]

Good talk! Seems like a industry guest talking about dynamodb in classroom.

[@VitalyZdanevich]

Thank you for dark slides.

[@Himanshu-mb8nl]

At 9:21, could the client be talking to the request router (RR) in an availability zone (AZ) and it isn't necessary that it has the leader storage node, and therefore the RR might have to send the request to the storage node leader to a different AZ. Nothing wrong with that but I wonder if there are any performance savings in having writes go directly to the RR in the AZ with the leader storage node.

[@galeop]

18:00 I guess we're talking about *global* 2ndary indexes here, and not *local* 2ndary indexes, correct ? Does this propagation of a new value from the main table to the 2ndary index happen asynchronously?

[@awssupport]

Hi Galeop, I appreciate your question and have raised this with the necessary team. Please check out this doc which may provide more insight into this: go.aws/3jETlOJ You're also welcome to reach out and discuss this matter on re:Post, by using this link: go.aws/aws-repost. ^ES

[@70lan7]

Best talk!

[@layer4down]

damn that was a good talk

[@Tommy-dd5pz]

I think it's looks like nanoseconds but actually milliseconds? 50:42

[@Mike-ci5io]

Does the replication log store the entire history of the data or just current state ?

[@ahmxtb]

usually the writeahead log only stores the portion of the data that's residing in the memory that's not yet flushed to disk. usually some databases that use Log-structured merge trees store most recent data in in-memory trees + writeahead log, and periodically flush to disk files.

[@frankren1333]

Trying to guess the PID controller part, seems it only needs the P(proportion)? let multiplier = 1.5 Let's say we want to allow roughly 60 seconds of 150% consumed over provisioning. Then on each iteration(say, a second), do: multiplier = multiplier + (provisioned - consumed) / provisioned / 60 # 60 is for 60 seconds multiplier = min(1.5, max(1, multiplier)) # clamp it between 1 & 1.5 This way the consumed can surge to 1.5 times provisioned and will slowly go down to 1, then keep as 1 until consumed is below provisioned and slowly bring multiplier back to 1.5

[@pemessh]

Great talk.

[@bud2725]

Nice. . . very nice.

[@kevin8918]

the last few sentences are like "we are hiring; come and work with us" lol

[@justmeandmy]

Yeah, and now that you've seen the talk you're already partially onboarded :P

[@youran]

Where can I download the PPT, please?

[@NR-bt7yz]

d1.awsstatic.com/events/reinvent/2019/Amazon_DynamoDB_Under_the_hood_of_a_hyperscale_database_DAT325.pdf (it's from 2019, but appears to be identical)

[@sagara9389]

Dynamodb is awsome for bigdata works but it is really hard to work with CRUD operations

[@dreamtheater_92]

What are you struggling with?

[@kulpranav]

Its just another kv data store. Why is it hard for crud?

[@galeop]

13:57

[@AbHIShEkUPAdhYaYshekup]

Perfect.

[@arifmalikoracledba9757]

Might it worth blowing your nose (away from the Mic ! ) & clearing you air waves before start of your session !