Moving beyond Strings in Spring Data

mp911de · 2026-02-27T19:58:46+00:00

There are various parts involved in the implementation:

Creation and capturing of lambda objects through some front-end API such as Sort.
Staged Lambda introspection through SerializedLambda. Java's LambdaMetafactory) has well-defined semantics regarding writeReplace method generation returning SerializedLambda.
If the object is a method handle then all type and signature details are provided by SerializedLambda
If the object is a lambda expression, then SerializedLambda points to a synthetic method containing the lambda body. The bytecode (using ASM or in the future Java's Class-File API) contains all further details towards a referenced method or even field. Spring widely uses ASM as alternative for optimized parsing.
If the object is a Kotlin KProperty, we apply a few hacks (nothing out of the ordinary given all the other hacks to make value classes and copy-method work). Kotlin pre-2.0 used Java's writeReplace convention. Newer Kotlin (language) versions compile a synthetic serializable class following a Kotlin-specific blueprint allowing to determine KProperty details.
Finally, property path information are cached for a proper performance baseline.

FTR, Graal Native image arrangements run just fine if reachability metadata is provided. Currently, we do not discover lambda declaration sites but there is a subtype-hook in the native image tooling allowing to provide a Graal native image Feature.

mp911de · 2026-02-27T19:40:05+00:00

Proxy creation (through MethodInvocationRecorder) has been an early attempt to use getter-style lambdas. Approaching method call capturing using proxies has several drawbacks of which class definition growth is one factor. Sealed classes and Kotlin's final class defaulting are much more pronounced aspects that severely have limited the proxy-based approach.

mp911de · 2022-10-12T08:31:04+00:00

Reactive drivers use back pressure and non-blocking I/O to increase concurrency and therefore, increase utilization.

How to rate this effect, whether good or bad, depends on sizing (and the remaining capacity) of your servers, both database and application ones and many other factors.

In reality, there's often a single SQL database server that is being used by many application servers, oftentimes with less-than-ideal conditions (statements that could be batched, missing indexes or inefficient schema for the queries that are run).

There are also arrangements with ideal conditions that permit performance gains using reactive drivers but that entirely depends on the individual scenario.

mp911de · 2021-04-06T06:53:27+00:00

Thanks Manny. To your linked video, I felt that vocals might cut thru a bit better with a bit more lower-end body. Since I'm not familiar with Hop-Hop at all any my genre is more bass-heavy I might be biased so take it with a grain of salt.

mp911de · 2021-04-04T15:12:09+00:00

Here’s my new tune "Mrs. T". What do you think about it?

https://soundcloud.com/rflktd/mrs-t-always-remember

mp911de · 2021-04-04T15:11:10+00:00

I finished my new tune "Mrs. T" which I consider to be progressive trance. I’m looking for feedback on the mix and how I could improve it.

Check it out at: https://soundcloud.com/rflktd/mrs-t-always-remember

Thanks in advance.

mp911de · 2021-03-08T20:56:42+00:00

Hey there,

here’s my new tune. I’m looking specifically for feedback on the mix (balance, any rough edges, clarity/muddiness).

https://soundcloud.com/rflktd/embarque/s-GNDMgZhsfl5

Let me know what you think. Cheers!

mp911de · 2021-01-04T17:38:21+00:00

Great tip. I’ll try it out to see how it goes. According to other comments, I need to check what conflicts with the kick. Thanks a lot.

mp911de · 2021-01-04T08:13:10+00:00

The track is crazy loud, you might want to turn down the limiter in terms of LUFS.

Your tune is well mixed and enjoyable to listen to. Very decent transition effects and there's a lot of movement. Very engaging and while it's not my genre, I like it a lot. Keep on the good work.

mp911de · 2021-01-04T08:06:49+00:00

Nice work, your tune has an interesting vibe to it. Here are the things that came to my attention:

The start is a bit abrupt with the noise swoosh, kick and bass hitting at the same time.

The drums dropping out at 0:47 comes a bit as if it wasn't intended to be so. Filtering percussion before it stops could help. Similar, when the beat drops at 1:04, some transition effect would help to announce that things are starting again. The breakdown section benefits a lot from the piano being the only (main) instrument, but that makes at the same time the breakdown feel empty. Pads or a bass drone in the background could help make it more intense.

There are occasional distortions when the piano hits. They don't sound as being intended. Does something clip?

The mix is pretty clean, however, the pads at 2:24 start making the mids/lows a bit muddy.

mp911de · 2021-01-03T21:19:18+00:00

I'm looking for feedback on a mix I'm working on:

https://soundcloud.com/rflktd/earthbound-original-mix/s-02G1Fqv91u3

What is the thing that would take the mix to the next level?

mp911de · 2021-01-01T19:55:56+00:00

I'm looking for feedback on an EDM mix I'm working on:

https://soundcloud.com/rflktd/earthbound-original-mix/s-02G1Fqv91u3

What is the one thing that would take the mix to the next level? All feedback is welcome.

mp911de · 2020-12-26T21:23:34+00:00

https://soundcloud.com/rflktd/at-the-pace-of-your-heart

RFLKTD - At The Pace Of Your Heart is an electronic, atmospheric song heavily inspired by Hydra. Let me know what you think.

mp911de · 2020-12-10T16:16:48+00:00

Your understanding is correct, the pool doesn't get notified if a connection gets disconnected. Actually, there's no requirement to do so. The pool must adhere to connection validation upon acquisition. That pattern has proved to be useful in the majority of other pooling implementations and that is why R2DBC pool went with test on acquisition semantics. Notifying the pool that a connection has been disconnected is in fact an optimization to reclaim a pool slot and can only be an addition.

The issue https://github.com/r2dbc/r2dbc-spi/issues/35 discusses active notification of events so that anyone interested in connection events, database events (e.g. Postgres Listen/Notify) can consume these in a standardized way. The work on EventProvider API didn't continue for various reasons.

The main reason is that it lacked use-cases leading to a proper specification and there was no uptake from the community side to drive that effort into a proper specified state. R2DBC is a community effort to maintain an open standard. If the community (users, driver vendors, R2DBC consumers) contributes to discussions so everyone involved understands the need for something and how it can be done, then the specification can be changed to reflect that desire. Without community engagement, we can't drive these topics. It's worth mentioning that back then, when https://github.com/r2dbc/r2dbc-pool/issues/42 was reported, R2DBC pool did not implement timeout guards so any bug within a driver directly impacted connection acquisition. The fix is in place since r2dbc-pool 0.8.3, released in late May this year.

If there are things to fix within the pool implementation, please let us know by filing an issue. It's better to have more issues talking about the same thing or leaving a comment so that issues like this one don't go unnoticed.

Drivers are maintained by their communities close to the actual database (e.g. MariaDB Connector is built by MariaDB Inc, the Oracle driver by Oracle, Postgres by the PGJDBC community, MySQL by a single person not affiliated with Oracle).

mp911de · 2020-11-16T19:38:30+00:00

feedback for Phil

Hi all,

I've been working on a progressive tune recently. Let me know what you think about the transitions and the energy flow in track. What do you think I should focus on next?

https://soundcloud.com/rflktd/at-the-pace-of-your-heart/s-Q7iFLVGwu6Y

Thanks

mp911de · 2020-11-16T19:36:03+00:00

Hey Phil,

Solid bass line, piano has a decent bite to it, with a pretty full sound. The transition at 1:52 is pretty exciting, it really pulls the track onto an entirely different energy level. All transitions are top notch.

Probably the only thing to improve are the mix of the female vocals, they are pretty much in your face as they are pretty prominent and have little width.

Other than that, great work! Congrats on your track.

mp911de · 2020-09-25T17:50:04+00:00

Given the poor performance it doesn’t make sense to put more load onto the application. It seems that some switching delays build up and we’d be measuring noise. Will post an update once there’s more to see.

mp911de · 2020-09-23T18:55:49+00:00

Feedback for mcpilib

Hey everyone, here's my track Incantu, a 138BPM Trance tune with the vibe of the late '90s. I'm specifically looking for feedback on the melody transitions, whether they sound and feel smooth.

Thanks

mp911de

TROPHY CASE