README
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mgots - Mango TS 
A Time Series data model API for Go and MongoDB
Mango TS is a Google Go package built on the mgo package which implements an optimized model for periodic and nonperiodic Time Series data stored in MongoDB.
Time series data
From Wikipedia:
A time series is a sequence of data points, typically consisting of successive measurements made over a time interval.
Periodic data
Period data appears in cronological order, at regular, predefined intervals.
Examples:
- Performance monitoring metrics every minute
- Scheduled tasks every hour
Periodic data is arrange into pages, each representing a linear segment of time, with a slot preallocated for each expected data point. For example, if the data interval is one minute and the page size is one hour, each page will contain 60 preallocated slots; one for each minute of the hour.
The model implemented in mgots is loosely based on Sandeep Parikh's time series schema design.
Nonperiodic data
Nonperiodic data appears in cronological order, but at irregular intervals. The data model used for periodic data is not appropriate for datasets of this kind as a significant amount of storage is wasted on preallocated intervals for which no data is entered.
Examples:
- Monitoring events at random
- User transactions at random
Nonperiodic data is arranged into a page until a configurable page size is exhausted (E.g. 4096 bytes) when a new page is allocated. Each page represents a linear segment of time, starting from the last entry point in the previous page, until the first entry point of the next page.
The model implemented in mgots is loosely based on Sylvain Wallez's model used in Actoboard.
Page sizes
A number of facters contribute to optimizing page sizes. These include but are no limited to:
- Disk alignment
- Alignment in memory of memory-mapped storage
- MongoDB's Power of 2 allocation strategy
- Memory consumption and network utilization when querying pages and returning data
Documentation
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Index ¶
- Constants
- Variables
- func BSONSize(v interface{}) int
- type Collection
- type DataPoint
- type DataPoints
- type NonperiodicCollection
- func (c *NonperiodicCollection) Append(seriesId interface{}, timestamp time.Time, value interface{}) error
- func (c *NonperiodicCollection) CreateSeries(seriesId interface{}, startTime time.Time) error
- func (c *NonperiodicCollection) Latest(seriesId interface{}) (DataPoint, error)
- func (c *NonperiodicCollection) Range(seriesId interface{}, minTime time.Time, maxTime time.Time) (DataPoints, error)
- func (c *NonperiodicCollection) Update(seriesId interface{}, value interface{}) error
Constants ¶
const ( PAGE_HEADER_SIZE = 110 // page header size in bytes (as per Object.bsonsize()) TIMESTAMP_SIZE = 66 // Timestamp data type size in bytes (including encapsulation) )
Variables ¶
var ErrDuplicateSeries = errors.New("Time series already exists with the specified ID")
var ErrInvalidPageSize = errors.New("Pages size must be greater than 256 bytes")
var ErrNoData = errors.New("No existing data to update")
var ErrSeriesNotFound = errors.New("Series not found with the specified collection")
Errors
var ErrTooOld = errors.New("The timestamp of the specified value is older than the most recent entry or the series does not exist.")
var ErrValueTooLarge = errors.New("The size value specified exceeds the maximum Time Series page size.")
Functions ¶
Types ¶
type Collection ¶
type Collection interface {
CreateSeries(seriesId interface{}, startTime time.Time) error
Append(seriesId interface{}, timestamp time.Time, value interface{}) error
Update(seriedId interface{}, value interface{}) error
Range(seriesId interface{}, minTime time.Time, maxTime time.Time) (DataPoints, error)
Latest(seriesId interface{}) (DataPoint, error)
}
func NewNonperiodicCollection ¶
func NewNonperiodicCollection(database *mgo.Database, name string, pageSize int) (Collection, error)
type DataPoints ¶
type DataPoints []DataPoint
type NonperiodicCollection ¶
type NonperiodicCollection struct {
PageSize int
// contains filtered or unexported fields
}
func (*NonperiodicCollection) Append ¶
func (c *NonperiodicCollection) Append(seriesId interface{}, timestamp time.Time, value interface{}) error
* value must have a consistent size
func (*NonperiodicCollection) CreateSeries ¶
func (c *NonperiodicCollection) CreateSeries(seriesId interface{}, startTime time.Time) error
func (*NonperiodicCollection) Latest ¶
func (c *NonperiodicCollection) Latest(seriesId interface{}) (DataPoint, error)
func (*NonperiodicCollection) Range ¶
func (c *NonperiodicCollection) Range(seriesId interface{}, minTime time.Time, maxTime time.Time) (DataPoints, error)
func (*NonperiodicCollection) Update ¶
func (c *NonperiodicCollection) Update(seriesId interface{}, value interface{}) error
Source Files