Questions tagged [cnosdb]

CnosDB is an open-source, distributed, temporal database. It can be used for IoT, DevOps, real-time analytics, and much more. This tag is for questions specifically related to CnosDB.

CnosDB is a time series database optimized for time-stamped or time series data. The versatility of CnosDB brings an easy and familiarity to developers and users to monitor physical systems, software systems, performance indicators, network data, sensor data and many other types of analytics data.

All of the code is open-sourced and available on GitHub.

Key features

  • High performance: CnosDB addresses the issue of time-series data expansion and theoretically supports unlimited time-series data. It supports aggregate queries along the timeline, including queries divided by equal intervals, queries divided by enumeration values of a column, and queries divided by the length of the time interval between adjacent time-series records. It also has caching capabilities for the latest data and the cache space can be configured for fast access to the latest data.
  • Easy to use: CnosDB provides clear and simple interfaces, easy configuration options, standard SQL support, seamless integration with third-party tools, and convenient data access functions. It supports schema-less writing mode and supports historical data supplement(including out of order writing).
  • Cloud native: CnosDB has a native distributed design, data sharding and partitioning, separation of storage and computing, Quorum mechanism, Kubernetes deployment and complete observability, ensuring final consistency. It can be deployed in public clouds, private clouds, and hybrid clouds. t also supports multi-tenancy and has role-based permission control. The computing and storage nodes support horizontal scaling.

Use cases

  • DevOps Monitoring: CnosDB's DevOps monitoring solution offers developers enhanced visibility across their infrastructures including servers, databases, microservices, cloud services to promote faster development cycles and increased agility in responding to market demands. With over 100 plugins, CnosDB offers extensive and transparent visibility into various application and infrastructure components, allowing teams across the organization to monitor system and application performance and health. The platform also features extensible instrumentation and open APIs for added flexibility and customization.
  • IoT Monitoring: CnosDB is designed to handle the constant flow of IoT data from multiple sources, typically associated with time-series workloads. The extensive use of IoT devices often results in real-time data reporting in streaming mode, presenting difficulties caused by their limited hardware performance and cache capacity. To overcome unexpected traffic surges, a database with high scalability and elasticity is necessary. CnosDB is a perfect fit for these situations, with features such as horizontal expansion and real-time analysis, ensuring optimal read and write performance, and accommodating flexible capacity needs.
  • Predictive Maintenance: CnosDB collects time-series data from sensors and other monitoring devices, stores it, and applies machine learning algorithms to analyze the data. This process enables the system to identify the health status and potential failure modes of equipment or systems. In scenarios such as oil and gas storage and transportation, nuclear power management, and bridge inspection, engineers can use CnosDB to predict and prevent equipment or system failures through predictive maintenance. They can take the necessary maintenance measures before a failure occurs.

Helpful links

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Does CnosDB support nested subqueries with aggregate functions or any equivalent solution?

Currently, I cannot do this in CnosQL: SELECT mean(max("speed")) FROM "wind" GROUP BY time(1m) I would like to count the average value of the maximum speed per minute over a period of time.
Munin
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Why is the time string returned by the cnosdb query different from the RFC3339 format of golang?

golang code: func main() { fmt.Println(time.Now().Format(time.RFC3339)) fmt.Println(time.Now().UTC().Format(time.RFC3339)) } golang output: 2023-09-01T10:56:32+08:00 2023-09-01T02:56:32Z cnosdb query result: | cnosdb | telegrafbfr …
learn_more
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Questions when using cnosdb's subscription function

In cnosdb, the subscription function supports the creation of a subscription from M to N. In this case, M has related data written, and a copy of the data will be synchronized to N. So when I create a subscription from N to M, a subscription ring…
HighFive
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Cnosdb: data with the same timestamp write twice succeeded but the last write cannot be queried

I had write some data in cnosdb and now I want to append a new column to my table. After using the RESTful write API, the new column can be queried but all values in the new column is just null. I think it is a bug, or caused by my mistake, which…
Darts
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How to calculate the average CPU usage

In prometheus I can write it like this rate(cpu.usage_user{}[1m]) But I don't know how to write it in CnosDB I would appreciate if you could provide an alternative function
Ivan
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How to access Cnosdb when using c++ or the c language?

How to access Cnosdb when using c++ or the c language? Does cnosdb provide c++/c client ? how can I use c++ or the c access the cnosdb? please provide a detail example/
xufei Alex
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Why does count function take 1000 seconds with a 70 million rows of data? How can I solve it?

cnosdb version 2.3. I used SQL command select count(*) from readings; to do a simple aggregate execution. And I got this result after waiting for more than 1000 seconds: +-----------------+ | COUNT(UInt8(1)) | +-----------------+ | 77784797 …
learn_more
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How to write multiple OpenTSDB data points into CnosDB?

I am helping my end users migrating some data interface from OpenTSDB to CnosDB and following this doc here.I could write one data point per quest as follows: curl -i -u "myUsername:myPassword" -XPOST…
Munin
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In the official document of CnosDB,What do "must_change_password" and "rsa_public_key" mean and how should they be used

In the section, it only describes how to create users, but there is no description and usage of "must_change_password" and "rsa_public_key" fields. I want to know how to use it The "must_change_password" field can be set when creating a user CREATE…
HighFive
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Got some warnings when i build Cnosdb source code, how to fix?

Got some warnings when i build Cnosdb source code, how to fix? warning: the following packages contain code that will be rejected by a future version of Rust: buf_redux v0.8.4, multipart v0.18.0, rustc-serialize v0.3.24 note: to see what the…
george
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Failed to switch database using CnosDB client

There are multiple databases in my database system, and the names of some databases are in mixed case. When I use the client to switch databases, it fails. To Reproduce(use cnosdb-cli) create database 'OceanicStation'; show databases; \c…
cosmic
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Cnosdb data node panic after restart data node

Cnosdb data node panic after restart data node. Env: version: 52cd675 1m2d load data 200g; To Reproduce: Steps to reproduce the behavior: select count(1) from readings; kill -9 data node processes pid; nohup ./target/release/cnosdb run -c 64 -m 256…
Baker
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Encountered some errors during cross compilation

I encountered some errors during cross compilation When I was building a program on aarch64-unknown-linux-gnu, I encountered the following error: error[E0308]: mismatched types --> common/models/src/meta_data.rs:258:37 | 258 | …
Ivan Gao
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Does CnosDB support batch query?

I checked CnosDB's RESTFUL API. I only found the interface /api/v1/sql to query data. But I didn't find a manual for bulk queries. Does CnosDB support one HTTP request to contain multiple SQLs and return the data of these SQLs together? Request body…
ZuoTiJia
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How to change the running status of a Cnosdb node

Does Cnosdb provide heartbeat detection between node and meta and the function of changing node status. For example, if the node has not communicated with meta for a period of time, the node needs to be taken offline. I checked the official…
baiqiubai
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