flink-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Taher Koitawala <taher.koitaw...@gslab.com>
Subject Re: [DISCUSS] Integrate Flink SQL well with Hive ecosystem
Date Fri, 12 Oct 2018 02:06:31 GMT
One other thought on the same lines was to use hive tables to store kafka
information to process streaming tables. Something like

"create table streaming_table (
bootstrapServers string,
topic string, keySerialiser string, ValueSerialiser string)"

Insert into streaming_table values(,",,", "KafkaTopicName", "SimpleStringSchema",

Create table processingtable(
//Enter fields here which match the kafka records schema);

Now we make a custom clause called something like "using"

The way we use this is:

Using streaming_table as configuration select count(*) from processingtable
as streaming;

This way users can now pass Flink SQL info easily and get rid of the Flink
SQL configuration file all together. This is simple and easy to understand
and I think most users would follow this.

Taher Koitawala

On Fri 12 Oct, 2018, 7:24 AM Taher Koitawala, <taher.koitawala@gslab.com>

> I think integrating Flink with Hive would be an amazing option and also to
> get Flink's SQL up to pace would be amazing.
> Current Flink Sql syntax to prepare and process a table is too verbose,
> users manually need to retype table definitions and that's a pain. Hive
> metastore integration should be done through, many users are okay defining
> their table schemas in Hive as it is easy to main, change or even migrate.
> Also we could simply choosing batch and stream there with simply something
> like a "process as" clause.
> select count(*) from flink_mailing_list process as stream;
> select count(*) from flink_mailing_list process as batch;
> This way we could completely get rid of Flink SQL configuration files.
> Thanks,
> Taher Koitawala
> Integrating
> On Fri 12 Oct, 2018, 2:35 AM Zhang, Xuefu, <xuefu.z@alibaba-inc.com>
> wrote:
>> Hi Rong,
>> Thanks for your feedback. Some of my earlier comments might have
>> addressed some of your points, so here I'd like to cover some specifics.
>> 1. Yes, I expect that table stats stored in Hive will be used in Flink
>> plan optimization, but it's not part of compatibility concern (yet).
>> 2. Both implementing Hive UDFs in Flink natively and making Hive UDFs
>> work in Flink are considered.
>> 3. I am aware of FLIP-24, but here the proposal is to make remote server
>> compatible with HiveServer2. They are not mutually exclusive either.
>> 4. The JDBC/ODBC driver in question is for the remote server that Flink
>> provides. It's usually the servicer owner who provides drivers to their
>> services. We weren't talking about JDBC/ODBC driver to external DB systems.
>> Let me know if you have further questions.
>> Thanks,
>> Xuefu
>> ------------------------------------------------------------------
>> Sender:Rong Rong <walterddr@gmail.com>
>> Sent at:2018 Oct 12 (Fri) 01:52
>> Recipient:Timo Walther <twalthr@apache.org>
>> Cc:dev <dev@flink.apache.org>; jornfranke <jornfranke@gmail.com>; Xuefu
>> xuefu.z@alibaba-inc.com>; vino yang <yanghua1127@gmail.com>; Fabian
>> Hueske <fhueske@gmail.com>; user <user@flink.apache.org>
>> Subject:Re: [DISCUSS] Integrate Flink SQL well with Hive ecosystem
>> Hi Xuefu,
>> Thanks for putting together the overview. I would like to add some more
>> on top of Timo's comments.
>> 1,2. I agree with Timo that a proper catalog support should also address
>> the metadata compatibility issues. I was actually wondering if you are
>> referring to something like utilizing table stats for plan optimization?
>> 4. If the key is to have users integrate Hive UDF without code changes to
>> Flink UDF, it shouldn't be a problem as Timo mentioned. Is your concern
>> mostly on the support of Hive UDFs that should be implemented in
>> Flink-table natively?
>> 7,8. Correct me if I am wrong, but I feel like some of the related
>> components might have already been discussed in the longer term road map of
>> FLIP-24 [1]?
>> 9. per Jorn's comment to stay clear from a tight dependency on Hive and
>> treat it as one "connector" system. Should we also consider treating
>> JDBC/ODBC driver as part of the component from the connector system instead
>> of having Flink to provide them?
>> Thanks,
>> Rong
>> [1].
>> https://cwiki.apache.org/confluence/display/FLINK/FLIP-24+-+SQL+Client
>> On Thu, Oct 11, 2018 at 12:46 AM Timo Walther <twalthr@apache.org> wrote:
>> Hi Xuefu,
>> thanks for your proposal, it is a nice summary. Here are my thoughts to
>> your list:
>> 1. I think this is also on our current mid-term roadmap. Flink lacks a
>> poper catalog support for a very long time. Before we can connect
>> catalogs we need to define how to map all the information from a catalog
>> to Flink's representation. This is why the work on the unified connector
>> API [1] is going on for quite some time as it is the first approach to
>> discuss and represent the pure characteristics of connectors.
>> 2. It would be helpful to figure out what is missing in [1] to to ensure
>> this point. I guess we will need a new design document just for a proper
>> Hive catalog integration.
>> 3. This is already work in progress. ORC has been merged, Parquet is on
>> its way [1].
>> 4. This should be easy. There was a PR in past that I reviewed but was
>> not maintained anymore.
>> 5. The type system of Flink SQL is very flexible. Only UNION type is
>> missing.
>> 6. A Flink SQL DDL is on the roadmap soon once we are done with [1].
>> Support for Hive syntax also needs cooperation with Apache Calcite.
>> 7-11. Long-term goals.
>> I would also propose to start with a smaller scope where also current
>> Flink SQL users can profit: 1, 2, 5, 3. This would allow to grow the
>> Flink SQL ecosystem. After that we can aim to be fully compatible
>> including syntax and UDFs (4, 6 etc.). Once the core is ready, we can
>> work on the tooling (7, 8, 9) and performance (10, 11).
>> @Jörn: Yes, we should not have a tight dependency on Hive. It should be
>> treated as one "connector" system out of many.
>> Thanks,
>> Timo
>> [1]
>> https://docs.google.com/document/d/1Yaxp1UJUFW-peGLt8EIidwKIZEWrrA-pznWLuvaH39Y/edit?ts=5bb62df4#
>> [2] https://github.com/apache/flink/pull/6483
>> Am 11.10.18 um 07:54 schrieb Jörn Franke:
>> > Would it maybe make sense to provide Flink as an engine on Hive
>> („flink-on-Hive“)? Eg to address 4,5,6,8,9,10. this could be more loosely
>> coupled than integrating hive in all possible flink core modules and thus
>> introducing a very tight dependency to Hive in the core.
>> > 1,2,3 could be achieved via a connector based on the Flink Table API.
>> > Just as a proposal to start this Endeavour as independent projects
>> (hive engine, connector) to avoid too tight coupling with Flink. Maybe in a
>> more distant future if the Hive integration is heavily demanded one could
>> then integrate it more tightly if needed.
>> >
>> > What is meant by 11?
>> >> Am 11.10.2018 um 05:01 schrieb Zhang, Xuefu <xuefu.z@alibaba-inc.com>:
>> >>
>> >> Hi Fabian/Vno,
>> >>
>> >> Thank you very much for your encouragement inquiry. Sorry that I
>> didn't see Fabian's email until I read Vino's response just now. (Somehow
>> Fabian's went to the spam folder.)
>> >>
>> >> My proposal contains long-term and short-terms goals. Nevertheless,
>> the effort will focus on the following areas, including Fabian's list:
>> >>
>> >> 1. Hive metastore connectivity - This covers both read/write access,
>> which means Flink can make full use of Hive's metastore as its catalog (at
>> least for the batch but can extend for streaming as well).
>> >> 2. Metadata compatibility - Objects (databases, tables, partitions,
>> etc) created by Hive can be understood by Flink and the reverse direction
>> is true also.
>> >> 3. Data compatibility - Similar to #2, data produced by Hive can be
>> consumed by Flink and vise versa.
>> >> 4. Support Hive UDFs - For all Hive's native udfs, Flink either
>> provides its own implementation or make Hive's implementation work in
>> Flink. Further, for user created UDFs in Hive, Flink SQL should provide a
>> mechanism allowing user to import them into Flink without any code change
>> required.
>> >> 5. Data types -  Flink SQL should support all data types that are
>> available in Hive.
>> >> 6. SQL Language - Flink SQL should support SQL standard (such as
>> SQL2003) with extension to support Hive's syntax and language features,
>> around DDL, DML, and SELECT queries.
>> >> 7.  SQL CLI - this is currently developing in Flink but more effort is
>> needed.
>> >> 8. Server - provide a server that's compatible with Hive's
>> HiverServer2 in thrift APIs, such that HiveServer2 users can reuse their
>> existing client (such as beeline) but connect to Flink's thrift server
>> instead.
>> >> 9. JDBC/ODBC drivers - Flink may provide its own JDBC/ODBC drivers for
>> other application to use to connect to its thrift server
>> >> 10. Support other user's customizations in Hive, such as Hive Serdes,
>> storage handlers, etc.
>> >> 11. Better task failure tolerance and task scheduling at Flink runtime.
>> >>
>> >> As you can see, achieving all those requires significant effort and
>> across all layers in Flink. However, a short-term goal could  include only
>> core areas (such as 1, 2, 4, 5, 6, 7) or start  at a smaller scope (such as
>> #3, #6).
>> >>
>> >> Please share your further thoughts. If we generally agree that this is
>> the right direction, I could come up with a formal proposal quickly and
>> then we can follow up with broader discussions.
>> >>
>> >> Thanks,
>> >> Xuefu
>> >>
>> >>
>> >>
>> >> ------------------------------------------------------------------
>> >> Sender:vino yang <yanghua1127@gmail.com>
>> >> Sent at:2018 Oct 11 (Thu) 09:45
>> >> Recipient:Fabian Hueske <fhueske@gmail.com>
>> >> Cc:dev <dev@flink.apache.org>; Xuefu <xuefu.z@alibaba-inc.com>;
user <
>> user@flink.apache.org>
>> >> Subject:Re: [DISCUSS] Integrate Flink SQL well with Hive ecosystem
>> >>
>> >> Hi Xuefu,
>> >>
>> >> Appreciate this proposal, and like Fabian, it would look better if you
>> can give more details of the plan.
>> >>
>> >> Thanks, vino.
>> >>
>> >> Fabian Hueske <fhueske@gmail.com> 于2018年10月10日周三 下午5:27写道:
>> >> Hi Xuefu,
>> >>
>> >> Welcome to the Flink community and thanks for starting this
>> discussion! Better Hive integration would be really great!
>> >> Can you go into details of what you are proposing? I can think of a
>> couple ways to improve Flink in that regard:
>> >>
>> >> * Support for Hive UDFs
>> >> * Support for Hive metadata catalog
>> >> * Support for HiveQL syntax
>> >> * ???
>> >>
>> >> Best, Fabian
>> >>
>> >> Am Di., 9. Okt. 2018 um 19:22 Uhr schrieb Zhang, Xuefu <
>> xuefu.z@alibaba-inc.com>:
>> >> Hi all,
>> >>
>> >> Along with the community's effort, inside Alibaba we have explored
>> Flink's potential as an execution engine not just for stream processing but
>> also for batch processing. We are encouraged by our findings and have
>> initiated our effort to make Flink's SQL capabilities full-fledged. When
>> comparing what's available in Flink to the offerings from competitive data
>> processing engines, we identified a major gap in Flink: a well integration
>> with Hive ecosystem. This is crucial to the success of Flink SQL and batch
>> due to the well-established data ecosystem around Hive. Therefore, we have
>> done some initial work along this direction but there are still a lot of
>> effort needed.
>> >>
>> >> We have two strategies in mind. The first one is to make Flink SQL
>> full-fledged and well-integrated with Hive ecosystem. This is a similar
>> approach to what Spark SQL adopted. The second strategy is to make Hive
>> itself work with Flink, similar to the proposal in [1]. Each approach bears
>> its pros and cons, but they don’t need to be mutually exclusive with each
>> targeting at different users and use cases. We believe that both will
>> promote a much greater adoption of Flink beyond stream processing.
>> >>
>> >> We have been focused on the first approach and would like to showcase
>> Flink's batch and SQL capabilities with Flink SQL. However, we have also
>> planned to start strategy #2 as the follow-up effort.
>> >>
>> >> I'm completely new to Flink(, with a short bio [2] below), though many
>> of my colleagues here at Alibaba are long-time contributors. Nevertheless,
>> I'd like to share our thoughts and invite your early feedback. At the same
>> time, I am working on a detailed proposal on Flink SQL's integration with
>> Hive ecosystem, which will be also shared when ready.
>> >>
>> >> While the ideas are simple, each approach will demand significant
>> effort, more than what we can afford. Thus, the input and contributions
>> from the communities are greatly welcome and appreciated.
>> >>
>> >> Regards,
>> >>
>> >>
>> >> Xuefu
>> >>
>> >> References:
>> >>
>> >> [1] https://issues.apache.org/jira/browse/HIVE-10712
>> >> [2] Xuefu Zhang is a long-time open source veteran, worked or working
>> on many projects under Apache Foundation, of which he is also an honored
>> member. About 10 years ago he worked in the Hadoop team at Yahoo where the
>> projects just got started. Later he worked at Cloudera, initiating and
>> leading the development of Hive on Spark project in the communities and
>> across many organizations. Prior to joining Alibaba, he worked at Uber
>> where he promoted Hive on Spark to all Uber's SQL on Hadoop workload and
>> significantly improved Uber's cluster efficiency.
>> >>
>> >>

View raw message