Databend Weekly

Databend aimed to be an open source elastic and reliable cloud warehouse, it offers blazing fast query and combines elasticity, simplicity, low cost of the cloud, built to make the Data Cloud easy.

Big changes

Below is a list of some major changes that we don't want you to miss.

Features

add proxy mode access check by @BohuTANG. (#3776)
add basic tokio-console support by @PsiACE. (#3739)
add generate command for bendctl by @kevinw66. (#3732)

Improvement

add more metrics to query_log by @dantengsky. (#3773)
make parquet reader works with only one stream reader by @dantengsky. (#3757)
fuse metadata cache by @Veeupup. (#3761)
UDF refinement by @lianghanzhen. (#3743)
cli up improvement by @sundy-li. (#3699)
replace arrow flight with gRPC by @ariesdevil. (#3606)
improve origin array builder & make nullable/no-nullable builder support by @Veeupup. (#3700)

Performance Improvement

improve performance of arithmetic functions by @zhyass (#3697)
table read performance tweaking by @dantengsky. (#3718)

Bug fixes

support as case-insensitive when create udf by @kevinw66. (#3703)

Tips

Let's learn a weekly tip from Databend.

Tracing in Databend

Databend using Rust's tracing ecosystem tokio-tracing to do log and profile.

Distributed tracing with Jaeger

Jaeger, is a distributed tracing platform. It can be used for monitoring microservices-based distributed systems.

4 steps to enable Jaeger monitor
- build databend-query: cargo build --bin databend-query
- run with DEBUG log level: LOG_LEVEL=DEBUG ./databend-query
- start jaeger: docker run -d -p6831:6831/udp -p6832:6832/udp -p16686:16686 jaegertracing/all-in-one:latest
- Open http://127.0.0.1:16686/
Jaeger Tracing Show

jaeger-tracing-show

Read More: https://databend.rs/dev/development/tracing#distributed-tracing-with-jaeger

Explore and diagnose with tokio-console

tokio-console is a diagnostics and debugging tool for asynchronous Rust programs.

3 steps to enable console subscriber
- build databend-query with rustflags & features: RUSTFLAGS="--cfg tokio_unstable" cargo build --bin databend-query --features tokio-console
- run with the log level of TRACE: LOG_LEVEL=TRACE databend-query
- run tokio-console
Run tokio-console to explore databend-query

query-console

Read More: https://databend.rs/dev/development/tracing#explore-and-diagnose-with-tokio-console

Changelogs

You can check the changelogs of Databend nightly to learn about our latest developments.

Ecosystem/Upstream

From open source, for open source. Our team is also committed to contributing to the Rust ecosystem and upstream dependencies.

arrow2 #73: add cargo check to benchmarks by @sundy-li.

Meet Us

Please join the DatafuseLabs Community if you are interested in Databend.

We are looking forward to seeing you try our code. We have a strong team behind you to ensure a smooth experience in trying our code for your projects. If you are a hacker passionate about database internals, feel free to play with our code.

You can submit issues for any problems you find. We also highly appreciate any of your pull requests.

This week in Databend #23