VRackDB - This is an embedded In Memory database designed for storing time series (graphs).

Features:

• Has a simple query format
• Always returns data as a graph.
• Very easy to use
• Very economical/very fast
• Aggregation and data modifiers
• Stores data in memory. If you close the program, the data will be lost
• Reserves metric memory, subsequent addition of metric data does not increase memory consumption
• Simple tool to track data and create alarm messages

Here are some examples of VRackDB applications:

• Plotting a graph of a file download
• Analyze application memory consumption
• Diagnose latency of HTTP/API/WebScoket and other requests
• Quantitative analysis of successful/unsuccessful operations per time interval
• SOC applications for computers and computer-based devices (multimeters, lab power supplies, etc.)
• Data caching for fast graph display/analysis
• Storage of time-based diagnostic information

For a quick start we recommend that you visit our guide

Русская версия

A local version of the guide is available

Motivation

In some situations, a simple database to store metrics with a simple query language is sorely lacking. For a general example, the Carbon + Whisper database was taken and a very simple in memort database was made using its analogy.

Why an in memory database? There are many tools that can be used to store metrics that store data optimized on disk. Such variants are not suitable when SD card is used as storage or there is no possibility to deploy a complex product. Sometimes it is necessary to embed the database into the application itself to display graphs that have no meaning after the application is closed. Such applications usually provide an opportunity to evaluate the rationality of saving the graph, and if a person needs it, the graph is saved in another format, and the data from memory are cleared after closing the application.

Support

The easiest way to support me or a project is to Donationalerts. In the donation, be sure to specify the project you want to support and the changes you would like to see to improve it. This will allow me to spend 1 hour of my time for every ~10$ donation. Each donation will be included in the next build of this project, it will also be read on my private stream.

Additional information

Even if I haven't made changes to the project for a long time, it doesn't mean that the project is dead. You can write to ponik_rf@mail.ru, I will try to respond as soon as possible.

Upgrade to version 3

If you are already using version 2, it is recommended that you check out official guide to upgrade to the new version.

Last changes

update 3.0.2

• Fixed error finding the real start of the layer

Collector

update 3.0.1

Interval

• Fixed a bug related to relative periods in classes other than Interval.
• Now in Interval.period it is possible to specify as a second parameter the time chunks that will be replaced in the period template

SingleDB

• Now in SingleDB.read method you can specify start and end as relative period. That is, there is no longer a need for the readAll method. You can simply specify read('test.metric', 'start:end', 300) instead of readAll('test.metric', 300).

update 3.0.0

SchemeDB

• Added SchemeDB class - Replaced the old Database class.
• Removed working with MetricTree (find method). Now you can use MetricTree without SchemeDB.
• The scheme method now uses named parameters
• It is now possible to define the CInterval parameter in the scheme method, which controls the minimal time unit (note: seconds, milliseconds, microseconds).

SingleDB

• Added SingleDB class - The simplest class for working with metrics. Each metric in this class can have different settings from other metrics. This class is the parent of the SchemeDB class

Database

• The class has been removed, now SchemeDB instead

Layer

• General refactoring - converted to TypeScript style
• Changed the initialization of the class. Named parameters are now used
• Size method removed, and replaced with Layer.length.
• All internal settings like interval, period, etc. are now read-only via “getters”.

Collector

• General refactoring - moved to TypeScript style
• The init method now uses named parameters
• Internal documentation update
• Collector methods now use the Interval that was specified when the metric was created
• Optimization of metrics settings storage
• All class properties are now defined as protected
• Added readFake method to retrieve irrelevant metrics
• Added info method that returns additional information about the metric (size, first write, number of attempts to write to the metric).

Interval

• Updated internal documentation, comments now better answer the question about what methods do.
• Added new concept of MTU - minimum time unit. MTU is a unit of time represented as an integer. For example, for the Interval class MTU = 1 second. For IntervalMs MTU = 1 millisecond, etc.
• Internal interfaces are now exported for use inside other extensible classes like IntervalMs
• Added getFactor() method which returns a time multiplier to get the MTU from the JS standard time. (Normally, JS uses milliseconds as the time. Factor to get MTU in Interval will be 0.001)
• Added 2 more intervals to the standard interval set - ms and us - millisecond and microsecond respectively
• Now if the result of interval conversion returns a fractional number - it will be rounded up.
• Fixed a problem with the partOfPeriod method. Previously it could perform only one type of operation in one expression, e.g. calculate 1m+10m+1h but if you needed to use both + and - it would cause an error.
• Added IntervalMs & IntervalUs classes to calculate Ms and Us as MTUs

Changes

update 3.0.1

Interval

• Fixed a bug related to relative periods in classes other than Interval.
• Now in Interval.period it is possible to specify as a second parameter the time chunks that will be replaced in the period template

SingleDB

• Now in SingleDB.read method you can specify start and end as relative period. That is, there is no longer a need for the readAll method. You can simply specify read('test.metric', 'start:end', 300) instead of readAll('test.metric', 300).

update 3.0.0

SchemeDB

• Added SchemeDB class - Replaced the old Database class.
• Removed working with MetricTree (find method). Now you can use MetricTree without SchemeDB.
• The scheme method now uses named parameters
• It is now possible to define the CInterval parameter in the scheme method, which controls the minimal time unit (note: seconds, milliseconds, microseconds).

SingleDB

• Added SingleDB class - The simplest class for working with metrics. Each metric in this class can have different settings from other metrics. This class is the parent of the SchemeDB class

Database

• The class has been removed, now SchemeDB instead

Layer

• General refactoring - converted to TypeScript style
• Changed the initialization of the class. Named parameters are now used
• Size method removed, and replaced with Layer.length.
• All internal settings like interval, period, etc. are now read-only via “getters”.

Collector

• General refactoring - moved to TypeScript style
• The init method now uses named parameters
• Internal documentation update
• Collector methods now use the Interval that was specified when the metric was created
• Optimization of metrics settings storage
• All class properties are now defined as protected
• Added readFake method to retrieve irrelevant metrics
• Added info method that returns additional information about the metric (size, first write, number of attempts to write to the metric).

Interval

• Updated internal documentation, comments now better answer the question about what methods do.
• Added new concept of MTU - minimum time unit. MTU is a unit of time represented as an integer. For example, for the Interval class MTU = 1 second. For IntervalMs MTU = 1 millisecond, etc.
• Internal interfaces are now exported for use inside other extensible classes like IntervalMs
• Added getFactor() method which returns a time multiplier to get the MTU from the JS standard time. (Normally, JS uses milliseconds as the time. Factor to get MTU in Interval will be 0.001)
• Added 2 more intervals to the standard interval set - ms and us - millisecond and microsecond respectively
• Now if the result of interval conversion returns a fractional number - it will be rounded up.
• Fixed a problem with the partOfPeriod method. Previously it could perform only one type of operation in one expression, e.g. calculate 1m+10m+1h but if you needed to use both + and - it would cause an error.
• Added IntervalMs & IntervalUs classes to calculate Ms and Us as MTUs

update 2.3.0

• Added method Collector.writeCount(metricId) which returns the number of records in the metric
• Added method Collector.start(metricId) which returns the expected start of the metric graph
• Added method Collector.end(metricId) which returns the expected end of the metric graph
• Now the size for each metric is calculated in advance, and Collector returns a ready-made value. This greatly speeds up the calculation of the occupied space of metrics in the scheme
• Added method Database.readAll(metricId, precision, func) Which returns data from the beginning of the metric record to the last record

update 2.2.3

• Fixes an issue where a non-existent value that was calculated by rounding was being captured.

update 2.1.0

This update adds a simple tool for tracking data in the database and generating alarm messages.

• Added Alerting class - for tracking data and generating alarm messages
• Added AlertQuery class - for defining query settings
• Added BasicCondition class - for defining the rule of alarm messages generation.
• Added abstract AlertCondtition
• Added isAggregateFunc method to MetricResult class.
• Interval class - removed unnecessary console.log class
• Added alias for Database class

update 1.6.0

In this update, changes have been made to make the API easier to understand. The Collector class now works more explicitly with metrics. Metric has been removed from all method names

• Changes to the Collector APi - read() now accepts seconds as the precision parameter.
• The Collector.hasMetric method has been renamed to Collector.has.
• The Collector.initMetric method has been renamed to Collector.init.
• The Collector.metricSize method has been renamed to Collector.size.
• Added Collector.layers method - returns layer settings and metric buffers Now all methods in the class refer to a specific metric and require the metric name as the first argument.

1.5.0

• Documentation fix
• Database.read & Database.readCustomRange now support specifying the desired number of metrics instead of the precision interval.
• Added Interval.getIntervalOfFixedCount method which returns the interval in seconds for a specified period to get a fixed metric count value.

1.3.3

• Update documentation
• Add configuration metricTree to Database class

1.3.2

• All comment in english

1.3.0

• Added classes for realizing different kinds of value and time storages
• It is now possible to specify the type of storage for collection and layer schema

1.2.0

• Added MetricResult class - Helper for processing the received results of metrics reads. It allows to aggregate the result of metric reads.
• Now it is possible to apply aggregation function for functions of readings from the database
• Added MetricWrite class - Helper for writing data to the database

• Now for functions of writing to the database the possibility of applying the write modifier is available

  1.1.0

• Added data relevance flag in the database response, in case the metric does not exist but the response should be generated, the relevance flag will be set to false and for each interval will be set to null.

• Added method readCustomRange(name: string, start: number, end: number, precision: string) to retrieve data for an arbitrary time period in seconds

• Added MetricTree metric tree storage class. The find method is now available for the Database class to find metrics paths.