src/go/plugin/go.d/modules/postgres/do_query_replication.go
// SPDX-License-Identifier: GPL-3.0-or-later
package postgres
import (
"fmt"
)
func (p *Postgres) doQueryReplicationMetrics() error {
if err := p.doQueryReplStandbyAppWALDelta(); err != nil {
return fmt.Errorf("querying replication standby app wal delta error: %v", err)
}
if p.pgVersion >= pgVersion10 {
if err := p.doQueryReplStandbyAppWALLag(); err != nil {
return fmt.Errorf("querying replication standby app wal lag error: %v", err)
}
}
if p.pgVersion >= pgVersion10 && p.isSuperUser() {
if err := p.doQueryReplSlotFiles(); err != nil {
return fmt.Errorf("querying replication slot files error: %v", err)
}
}
return nil
}
func (p *Postgres) doQueryReplStandbyAppWALDelta() error {
q := queryReplicationStandbyAppDelta(p.pgVersion)
var app string
return p.doQuery(q, func(column, value string, _ bool) {
switch column {
case "application_name":
app = value
p.getReplAppMetrics(app).updated = true
default:
// TODO: delta calculation was changed in https://github.com/netdata/netdata/go/plugins/plugin/go.d/pull/1039
// - 'replay_delta' (probably other deltas too?) can be negative
// - Also, WAL delta != WAL lag after that PR
v := parseInt(value)
if v < 0 {
v = 0
}
switch column {
case "sent_delta":
p.getReplAppMetrics(app).walSentDelta += v
case "write_delta":
p.getReplAppMetrics(app).walWriteDelta += v
case "flush_delta":
p.getReplAppMetrics(app).walFlushDelta += v
case "replay_delta":
p.getReplAppMetrics(app).walReplayDelta += v
}
}
})
}
func (p *Postgres) doQueryReplStandbyAppWALLag() error {
q := queryReplicationStandbyAppLag()
var app string
return p.doQuery(q, func(column, value string, _ bool) {
switch column {
case "application_name":
app = value
p.getReplAppMetrics(app).updated = true
case "write_lag":
p.getReplAppMetrics(app).walWriteLag += parseInt(value)
case "flush_lag":
p.getReplAppMetrics(app).walFlushLag += parseInt(value)
case "replay_lag":
p.getReplAppMetrics(app).walReplayLag += parseInt(value)
}
})
}
func (p *Postgres) doQueryReplSlotFiles() error {
q := queryReplicationSlotFiles(p.pgVersion)
var slot string
return p.doQuery(q, func(column, value string, _ bool) {
switch column {
case "slot_name":
slot = value
p.getReplSlotMetrics(slot).updated = true
case "replslot_wal_keep":
p.getReplSlotMetrics(slot).walKeep += parseInt(value)
case "replslot_files":
p.getReplSlotMetrics(slot).files += parseInt(value)
}
})
}