> Besides the above, when we merge this pr, we posted the design in the > feishu[4] and discussed it online as least two times, and emailed and > discussed it with everyone[5], it has been passed 10 days.
I think I know this and I have shown my concern about the possible harm of this featuer to IoTDB's edge mode... > 1) how many side-effects the feature will bring; > We have done some tests under[1], which says with 20 databases and 1 user > when we set `quota_enable` to true to enable the multi-tenancy feature, the > write performance is only slowed down 1.75%, the read latency has not much > difference, we will do more tests to show the side-effects in the feature. The experiment is rather simple... When we really want to show the added codes having no side-effects, all the exepriemnt settings should follow a rule that how to fully expose the possible problems. For example, as mult-tenancy limits the available # of devices, timeseries, and the spaces of disk, it should have side-effect on create new device/timeseries, and writing new data. So, - what is the side effect when we manually create a time series? - what is the side effect when we use automatical creating a time series? - what is the side effect when we write new data? (as the data can be compressed when it is flushed on disk in async mode, how to check the disk space?). Besides, as it impaces each write operation, we need to focus on write operstions which's batchsize=1. This discuss is not for getting "+1" or "-1" (though anyone can reply the vote..). I just want to discuss that do we REALLY consider and analyze the feature and the implementation carefully? If not, then this big feature is not the time to be merged (and I will call a vote then), and then let's rethink it and make it really available together. If yes, we also need to rethink it and improve it for better performance. Best, ----------------------------------- Xiangdong Huang School of Software, Tsinghua University Chao Wang <ccgow...@163.com> 于2023年4月10日周一 19:14写道： > > Agree with Houliang's opinion. > > > Thanks! > > > Chao Wang > BONC ltd > On 4/10/2023 19:01，Houliang Qi<neuyi...@163.com> wrote： > -1 > > First of all, thanks Xiangdong for pointing out IoTDB's Charter. > > "RESOLVED, that the Apache IoTDB Project be and hereby is > responsible for the creation and maintenance of software > related to an IoT native database with high performance > for data management and analysis, on the edge and the cloud." > > As the charter post, IoTDB can be deployed in the cloud, this is why we > deploy the multi-tenancy feature. > > The cloud can be a public or private cloud if we can deploy only one IoTDB > cluster, and manage multi databases and users with different resources, which > will simplify the maintenance. > > -> 1) how many side-effects the feature will bring; > > We have done some tests under[1], which says with 20 databases and 1 user > when we set `quota_enable` to true to enable the multi-tenancy feature, the > write performance is only slowed down 1.75%, the read latency has not much > difference, we will do more tests to show the side-effects in the feature. > > -> 2) how to reduce the effect when IoTDB is deployed on the edge. > > We supply one switch about this feature, called `quota_enable`, by default > this value is false, so it has no effect when IoTDB is deployed on the edge. > This also answers Jinrui's doubt. > > -> 3) some checks failed on WinOS, are they irrelevant? > > No, I think they are not irrelevant, the false check message is about the > Compaction module, and > I see the former pr[2][3] which have been merged 4 days ago has the same > issue, so I suspect that the compaction module has occasional bugs > > -> 4) The feature SHOULD be discussed carefully in the community, rather that > submit PRs and merged after some reviews. > > Besides the above, when we merge this pr, we posted the design in the > feishu[4] and discussed it online as least two times, and emailed and > discussed it with everyone[5], it has been passed 10 days. > > > The IoTDB community is open and different opinions are welcome. After all, we > all have the same original intention of wanting IoTDB's features to be more > diverse. > > [1] https://apache-iotdb.feishu.cn/docx/DbqCd8t3EoxlCFx1yYicd9N4n4s > [2] https://github.com/apache/iotdb/actions/runs/4625220921/jobs/8181102446 > [3] https://github.com/apache/iotdb/actions/runs/4531046594/jobs/7980725316 > [4] https://apache-iotdb.feishu.cn/docx/doxcnKOYKDmJ40FpVnVsPMd3nTg > [5] https://lists.apache.org/thread/y6dqcm2o7qk0nbkllb61bp8cv6d3m1h7 > > > > > > Thanks, > --------------------------------------- > Houliang Qi > BONC, Ltd > > > ---- Replied Message ---- > | From | 张金瑞<329920...@qq.com.INVALID> | > | Date | 04/10/2023 15:03 | > | To | dev<dev@iotdb.apache.org> | > | Subject | Re：[discuss] consider revert the feature of multi-tenancy | > +1, > > > Agree with Xiangdong's opinion. > And on the other hand, checking this PR's side effects may take lot of > time and during this period, there may be lots of users using latest > code to deploy/upgrade their systems. So the best practice is reverting this > PR until the side-effect is eliminated > > > > Thanks, > Zhang Jinrui，Apache IoTDB PMC > > > > Original > > > > From:"Xiangdong Huang"< saint...@gmail.com >; > > Date:2023/4/10 10:05 > > To:"dev"< dev@iotdb.apache.org >; > > Subject:[discuss] consider revert the feature of multi-tenancy > > > Hi all, > > I see the multi-tenancy feature is merged, and several committers made > a lot of contributions on that. > > As multi-tenancy is quite a big feature, which may change IoTDB's > position. The feature SHOULD be discussed carefully in the community, > rather that submit PRs and merged after some reviews. > > Therefore, I call to revert the PR and discuss ASAP about the feature > after that. > > At least, the proposer need to answer the following questions, > 1) how many side-effect the feature will bring; > 2) how to reduce the effect when IoTDB is deployed on the edge. > 3) some checks failed on WinOS, are they irrelevant? > > I don't mean of rejecting any big contribution to IoTDB or harming the > community's diversity, but accepting this feature is really big > decision and it deserves us to take time to deliberate. > > > Attached IoTDB's Charter: > "RESOLVED, that the Apache IoTDB Project be and hereby is > responsible for the creation and maintenance of software > related to an IoT native database with high performance > for data management and analysis, on the edge and the cloud." > > > [1] https://github.com/apache/iotdb/pull/9534/checks > > Best, > ----------------------------------- > Xiangdong Huang > School of Software, Tsinghua University
