[Hold for payment 2021-08-17] [Performance] Optimize AsyncStorage on Android

[arielgreen]

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Problem

Though not carefully benchmarked, it's pretty obvious that the Android app is slow -- to start, to use, etc. And all things being equal, it would be better if it were faster. We don't know exactly what fraction of that time is spent reading/writing data from/to disk, but it's nonzero, and if it were faster, it would be a rising tide that floats all boats.

Solution

Do the following:

1. Create a standalone RN app that benchmarks AsyncStorage. I think it should have three buttons, each of which outputs timing information to a log:
   a. Reset - Deletes the database on disk
   b. Write Sequential - Inserts a random number into keys 0 to 1M sequentially
   c. Read Sequential - (only active if there is a database) Read rows 0 to 1M sequentially
2. Do some basic tests on both Android and iOS, and record timing from these scenarios in order:
   a. Cold write sequential - Reset the database, reboot the phone, then start the app and tap "Write Sequential". This will measure the ability to write to a "cold" disk that has nothing cached.
   b. Warm write - After doing "Cold write", tap "Write Sequential" again and see how overwriting the same database (presumably that is already cached) differs in performance.
   c. Warm read - After "Warm write", tap "Read Sequential" and see how reading a warmed-up file performs.
   d. Cold read - Reboot the phone, open the app, then tap "Read Sequential" again, to see how read performance differs when the file isn't cached
3. Refactor AsyncStorage on Android to implement each of the suggested optimizations described here, and re-run the benchmark after each to see which helps and by how much, namely:
   a. Stored procedures (to avoid recompiling SQL every time)
   b. PRAGMA synchronous=OFF;
   c. PRAGMA mmap_size=(1010241024); // 10MB memory map
   d. Update the "Sequential Read" test to read keys in batches of 100, and re-test with the stock implementation (which just calls AsyncStorage.get() multiple times). Then implement a native version of AsyncStorage.multiGet() that makes a single query to SQLite, and re-test.
4. Once we've found the winning combo (if any), submit to the React Native mainline to see if we can get them to merge it. However, you'll get paid whether or not they do.

Also, test a native version of AsyncStorage.mutliGet() that does it all in one query.

Upwork job post

View all open jobs on Upwork

[MelvinBot]

Triggered auto assignment to @tgolen (Exported), see https://stackoverflow.com/c/expensify/questions/7972 for more details.

[mateusbra]

Proposal

I will make the step by step witth a standalone RN APP as mentioned and develop what was described here.
In addition I will compare the benchmarks, analyze and obtain the best config to improve the performance result at maximum.

Finally I will implement the AsyncStorage.multiGet().

[arielgreen]

@mateusbra Please see our Contributing Guidelines for an explanation of what we're looking for in a proposal.

[arielgreen]

@kidroca is this something you'll be working on as part of #2762?

[kidroca]

@arielgreen
It's planned to happen after #2762 and it's not part of that scope: https://expensify.slack.com/archives/C01GTK53T8Q/p1620172402387600?thread_ts=1620065578.311900&channel=C01GTK53T8Q&message_ts=1620172402.387600

Additionally, after this is done, @kidroca would you be willing to pick up that AsyncStorage optimization project? After all, we still need "cold" reads to be fast, and your timing shows that Android significantly slower than iOS, for (probably) easily solvable reasons.

[arielgreen]

@kidroca gotcha — thanks.

[arielgreen]

Job posting for this has expired. I'll repost to Upwork when we're ready to move forward with this one (I.e., when #2762 is complete).

[arielgreen]

@kidroca Are you ready to move forward with this? If so, I’ll recreate the Upwork posting and send over an invite.

[quinthar]

I don't think we should wait for @kidroca -- let's go ahead and get someone working on it asap! It would be great if it could be @kidroca, but it sounds like @mateusbra might also be interested (and probably a whole bunch more).

[kidroca]

@arielgreen

@kidroca Are you ready to move forward with this? If so, I’ll recreate the Upwork posting and send over an invite.

Yes, I am

Proposal

I've already worked on benchmarking and performance capturing logic.
It can be reused even if we're not using Onyx for the timings that should be captured here
My plan is to provide aggregated timing data the way I did here: #2762 (comment)

I will use a physical Android device - Samsung Galaxy S7 Edge Android 8.0 that tends to have a slow read speed at the moment

I'll work and submit a PR against E.cash fork of react-native: https://github.com/Expensify/react-native

One question, where should I push the "sample" app from step 1) Create a standalone RN app that benchmarks AsyncStorage

• should I create an example folder and submit it with my PR? It should not be merged to main, but maybe it can live on a separate branch?

[tgolen]

Create a standalone RN app that benchmarks AsyncStorage

For this, I was thinking that it would live in a completely separate repo that you own (a free repo is fine). Would that work?

[kidroca]

For this, I was thinking that it would live in a completely separate repo that you own (a free repo is fine). Would that work?

Sure

[arielgreen]

Upwork posting here.

[kidroca]

Here's some benchmark information so far:

Setup

• Device: Samsung Galaxy S7 Edge (Released 2016) Android 8.0
• Build mode: production (also JS DEV = false)
• Operations run in sequence one after the other

Before AsyncStorage updates

10, 000 Operations

50, 000 Operations

Questions

Do you still want me to do 1M tests, for an average of 16ms it would take about 4.5hrs to write 1M entries?

I think the fast speeds we see here are due to the fact that operations run in sequence and wait for each other, I've tried saving larger texts (1kb each) and the time is about the same (16.9ms per write, 8.3ms per read)
The problem with E.cash being slow on Android seems to be that AsyncStorage does not handle parallel requests very well and E.cash/Onyx blast it with as many calls as they need. Maybe we should think something in this direction - optimize (or add) batching in AsyncStorage so that many parallel request does not degrade its performance. This could be alleviated as well by using multiGet in Onyx when that's possible, point 2 here: Expensify/react-native-onyx#78

Do you want to make a different benchmark that tries to write using as many parallel requests as possible in an attempt to review the issue I've described above?

cc @quinthar @tgolen

[kidroca]

The relatively fast times got me to double check what versions of AsyncStorage are used, and I've discovered that E.cash is using a version of AsyncStorage that was abandoned by the community

E.cash and Onyx use: "@react-native-community/async-storage": "^1.11.0" which resolves to v1.12.1 the latest version you'll ever get from that repository
https://github.com/Expensify/Expensify.cash/blob/854c9bf0420d4dd3036dc7610adf0c9cf0778521/package.json#L41

AsyncStorage was moved to "@react-native-async-storage/async-storage": "^1.15.5": react-native-async-storage/async-storage#507 (comment) - that's the version I've used for benchmarking as well

• I've downgraded to the deprecated version and ran the benchmarks again, the times are slightly slower 19ms on average for writes and 9.5ms for reads

After a bit more investigation I've found this: AsyncStorage is moving away from the SQLiteOpenHelper and switches to Room - https://react-native-async-storage.github.io/async-storage/docs/advanced/next

The Room persistence library provides an abstraction layer over SQLite
https://developer.android.com/training/data-storage/room

The latest version of AsyncStorage already has support for Room and it can be enabled following these steps: https://react-native-async-storage.github.io/async-storage/docs/advanced/next#enabling

Some additional point we should check with these discoveries:

• Do you still want to contribute to AsyncStorage when it's not a part of @react-native-community
• IMO we should not add the intended optimizations on the old code since it's going to be dropped. At the same time I'm not sure whether Room provides the needed low level access to set the options
• is Room covering the updates we're trying to do here? I think Room being an official part of the Android documentation should be a solid library and be optimized enough.
• should we run a benchmark with the AsyncStorage/next enabled ?
• should we as well try and see how would E.cash run with AsyncStorage/next?
• investigate whether the new implementation uses JSI?

I'll investigate the new source of AsyncStorage and try to answer some of the points above
cc @quinthar @tgolen

Edit: Clarification the benchmarks above are not using Room. It has to be enabled explicitly

[quinthar]

Do you still want to contribute to AsyncStorage when it's not a part of @react-native-community

Wow, amazing find. Yes, let's not invest in abandoned code. Let's definitely redo the benchmark with the latest and greatest.

[tgolen]

Yeah, I agree. That's a good find, I had no idea it was abandoned. Let's first see if we can upgrade to the latest version, ensure there are no regressions, and then start benchmarking on that.

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On Mon, Jul 5, 2021 at 1:13 PM David Barrett ***@***.***> wrote: Do you still want to contribute to AsyncStorage when it's not a part of @react-native-community <https://github.com/react-native-community> Wow, amazing find. Yes, let's not invest in abandoned code. Let's definitely redo the benchmark with the latest and greatest. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#2667 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJMAB3ROM73CCDNEHZ2KK3TWH765ANCNFSM44BATT7Q> .

[kidroca]

I've updated my fork of Onyx with the latest AsyncStorage and did the same with E.cash
I've runned with enabling next (Room) and without it, but I can't see any noticeable improvements

• btw (next/Room) would affect Android only as it's just for that platform

I'll post some before/after benchmark data of E.cash init

In the meantime do you want me to open a PR to update Onyx and E.cash with the new AsyncStorage repo?
We can decide if we want next enabled or not after some more tests

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I might have misled you with "abandoned", I think AsyncStorage is still a project maintained by the react-native community but it was moved out for the reasons they've discussed (on what to stay in/out)

[tgolen]

Yeah, go ahead and do a PR to update that lib. Even if it's not totally abandoned, I think we want to keep whichever is the most active and the most generally accepted as "official".

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On Tue, Jul 6, 2021 at 11:19 AM Peter Velkov ***@***.***> wrote: I've updated my fork of Onyx with the latest AsyncStorage and did the same with E.cash I've runned with enabling next (Room) and without it, but I can't see any noticeable improvements - btw (next/Room) would affect Android only as it's just for that platform I'll post some before/after benchmark data of E.cash init In the meantime do you want me to open a PR to update Onyx and E.cash with the new AsyncStorage repo? We can decide if we want next enabled or not after some more tests ------------------------------ I might have misled you with "abandoned", I think AsyncStorage is still a project maintained by the react-native community but it was moved out for the reasons they've discussed (on what to stay in/out) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#2667 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJMAB2H5QTEE35YXXR27XTTWM3JLANCNFSM44BATT7Q> .

[kidroca]

I've posted a comparison of Onyx.get timings per each AsyncStorage version: Expensify/react-native-onyx#85 (comment)

• no noticeable improvements when using the Room version

[kidroca]

I've listed what have been done here: #2667 (comment)

And now we're at

I've proposed changes in Onyx here More improvements for Onyx.connect (After cache) react-native-onyx#78 that will use multiGet instead of foreach-ing which results in parallel requests. This might alleviate work enough so that the rest of the parallel calls are not an issue

I've started working on that task, but discovered that though batching improves timings they are still far from 9-16ms for reads. Since then I've studied Onyx more and found some other places where it can improve and opened this PR #88

Before continuing with further work I would like to complete my contract for this assignment
You've closed my PR so that I can open a few separate ones where we can test each change and merge stuff gradually to Onyx, I'll be happy to do that under a new milestone

[arielgreen]

@kidroca All set; approved and paid the original milestone and added an additional milestone. Please proceed.

[kidroca]

@arielgreen Thanks

I'm continuing with opening the first PR of the series
I'll also open issues that are not yet on E.cash board

[marcaaron]

PRs related to capturing metrics have been merged

[arielgreen]

All good @MelvinBot

[marcaaron]

Just giving a brief update of where we are at with this. 2 more PRs have been merged:

1. PR to improve metrics output
2. Another PR to defer some Onyx.connect() calls while we wait for defaultKeysStates to be set

@kidroca I will create a PR to get that change into Expensify/App if you want to start working on the next PR which is

Prevent unnecessary writes when data has not changed by adding _.isEqual()

Sound good?

[kidroca]

@marcaaron
Thanks, the 3rd PR was merged as well
These 3 are ready:

1. PR to improve metrics output
2. Another PR to defer some Onyx.connect() calls while we wait for defaultKeysStates to be set
3. Prevent unnecessary writes when data has not changed by adding _.isEqual()

Next is "LRU Cache update", I'll try to get the withLocalize change ready as well so we can see the full improvements: #4253

[marcaaron]

Nice, so, I've updated the open PR to include the latest changes and did another set of user timing tests on release builds.

The 2nd PR did not yield anything significant in terms of user time. But I did have to fix a broken test. No issues observed besides that.

The 3rd improved chat switch times by ~250ms on Android 🎉

[MelvinBot]

@tgolen, @kidroca, @arielgreen it looks like no one is assigned to work on this job.
Please double the price or add a comment stating why the job isn't being doubled.

[kidroca]

I'm working on this. Will submit my last PR tomorrow.

[arielgreen]

Thanks @kidroca — ignore MelvinBot's comment above, we were testing something.

[kidroca]

The 4th of the planned PRs was merged: Expensify/react-native-onyx#93
I'll open a PR to update Expensify/App on Monday

@arielgreen This would complete my current Upwork milestone. I think I can work on any approved future tasks under my hourly contract, we can keep this ticket open if necessary, though everything listed would have it's own issue

We've identified some additional work related to storage performance that's worth pursuing

1. Onyx multi get and batching - [Performance] Onyx.get batching react-native-onyx#84
2. Onyx hydration - [Performance] Onyx: Hydrate cache with all finite size keys before init #4433
3. Try a JSI storage implementation - https://expensify.slack.com/archives/C01GTK53T8Q/p1628181643026200?thread_ts=1628106063.148700&cid=C01GTK53T8Q (Github ticket to be created)
4. Aggregated OnyxContext to make withOnyx rendering faster - [Performance] [Audit] withOnyx causes bursts of commits, impeding performance #4101 (comment)

@marcaaron 1 and 2 might become unneeded if the experiment on 3 is successful - JSI can be called directly - we can assign component state in the constructor. Same is true for browser's local storage, though we'll have to fill some of the functionality (like multi merge) that AsyncStorage provided

[marcaaron]

@kidroca I agree we should start investigating the JSI storage implementation. Probably the easiest way to prove the value is to patch Onyx to use MMKV and see if things improve then go from there.

[kidroca]

The 4th PR was merged here: #4509

• @arielgreen this completes the milestone in Upwork, there was one regressions that was handled, I'm OK to give this more time in case there are other regressions, but just want to bring up that new work is tracked separately

We've started work/discussions on the items proposed above #2667 (comment)

[arielgreen]

Excellent, thanks @kidroca. The 7-day period ends tomorrow for that one, so I'll pay out the milestone and close out that contract tomorrow.

@marcaaron since this work is continuing, is it helpful to leave this GH issue open as a master issue to track all these improvements going forward?

[marcaaron]

is it helpful to leave this GH issue open as a master issue to track all these improvements going forward

I think we can just close this one out.

We are looking into some improvements to the storage layer here and a few other issues tagged with [Performance] in the title.

[arielgreen]

Paid.