cassandra

Documentation

Index

• type Devops
  • func NewDevops(start, end time.Time, scale int) *Devops
  • func (d *Devops) GenerateEmptyQuery() query.Query
  • func (d *Devops) GroupByOrderByLimit(qi query.Query)
  • func (d *Devops) GroupByTime(qi query.Query, nHosts, numMetrics int, timeRange time.Duration)
  • func (d *Devops) GroupByTimeAndPrimaryTag(qi query.Query, numMetrics int)
  • func (d *Devops) HighCPUForHosts(qi query.Query, nHosts int)
  • func (d *Devops) LastPointPerHost(qi query.Query)
  • func (d *Devops) MaxAllCPU(qi query.Query, nHosts int)

Types

type Devops

type Devops struct {
	*devops.Core
}

Devops produces Cassandra-specific queries for all the devops query types.

func NewDevops

func NewDevops(start, end time.Time, scale int) *Devops

NewDevops makes an Devops object ready to generate Queries.

func (*Devops) GenerateEmptyQuery

func (d *Devops) GenerateEmptyQuery() query.Query

GenerateEmptyQuery returns an empty query.Cassandra

func (*Devops) GroupByOrderByLimit

func (d *Devops) GroupByOrderByLimit(qi query.Query)

GroupByOrderByLimit populates a query.Query that has a time WHERE clause, that groups by a truncated date, orders by that date, and takes a limit: SELECT date_trunc('minute', time) AS t, MAX(cpu) FROM cpu WHERE time < '$TIME' GROUP BY t ORDER BY t DESC LIMIT $LIMIT

func (*Devops) GroupByTime

func (d *Devops) GroupByTime(qi query.Query, nHosts, numMetrics int, timeRange time.Duration)

GroupByTime selects the MAX for numMetrics metrics under 'cpu', per minute for nhosts hosts, e.g. in pseudo-SQL:

SELECT minute, max(metric1), ..., max(metricN) FROM cpu WHERE (hostname = '$HOSTNAME_1' OR ... OR hostname = '$HOSTNAME_N') AND time >= '$HOUR_START' AND time < '$HOUR_END' GROUP BY minute ORDER BY minute ASC

func (*Devops) GroupByTimeAndPrimaryTag

func (d *Devops) GroupByTimeAndPrimaryTag(qi query.Query, numMetrics int)

GroupByTimeAndPrimaryTag selects the AVG of numMetrics metrics under 'cpu' per device per hour for a day, e.g. in pseudo-SQL:

SELECT AVG(metric1), ..., AVG(metricN) FROM cpu WHERE time >= '$HOUR_START' AND time < '$HOUR_END' GROUP BY hour, hostname ORDER BY hour

func (*Devops) HighCPUForHosts

func (d *Devops) HighCPUForHosts(qi query.Query, nHosts int)

HighCPUForHosts populates a query that gets CPU metrics when the CPU has high usage between a time period for a number of hosts (if 0, it will search all hosts), e.g. in pseudo-SQL:

SELECT * FROM cpu WHERE usage_user > 90.0 AND time >= '$TIME_START' AND time < '$TIME_END' AND (hostname = '$HOST' OR hostname = '$HOST2'...)

func (*Devops) LastPointPerHost

func (d *Devops) LastPointPerHost(qi query.Query)

LastPointPerHost finds the last row for every host in the dataset

func (*Devops) MaxAllCPU

func (d *Devops) MaxAllCPU(qi query.Query, nHosts int)

MaxAllCPU selects the MAX of all metrics under 'cpu' per hour for nhosts hosts, e.g. in pseudo-SQL:

SELECT MAX(metric1), ..., MAX(metricN) FROM cpu WHERE (hostname = '$HOSTNAME_1' OR ... OR hostname = '$HOSTNAME_N') AND time >= '$HOUR_START' AND time < '$HOUR_END' GROUP BY hour ORDER BY hour