TopolearnLists of instances, pods, endpoints or customers are tables, and a table needs its data in a different shape than a graph does.
A Table shows data frames as rows and columns. The first thing to get right is the shape of the data. A Prometheus range query gives one frame per series with a time column, which the table shows as separate frames with a selector; what you usually want is one row per series, so set the query Type to instant and Format to Table. Each label becomes a column, plus Time and Value. For several queries, the Merge transformation combines them into one table, and Organize fields renames and hides columns.
Useful options:
- Column filter adds a filter control per column; pagination and a footer with calculations (Total, Mean, Count) help long tables.
- Column width, minimum width and cell height; align left, center or right.
- Cell options, set per column with overrides: coloured text or coloured background driven by thresholds, a gauge inside the cell, sparkline (needs the Time series to table transformation), JSON view for nested objects, image, or an Actions/data link cell.
- Value mappings turn
0/1into "down"/"up" with colours, which reads far better than numbers.
Sorting is by clicking a header, or permanently with the Sort by transformation. Hide the Time column of instant queries; it only holds the evaluation time.
Tables render everything the query returned, so keep result sets small with topk() or SQL LIMIT; thousands of rows make the browser crawl and nobody reads them anyway.
Example
{
"type": "table",
"title": "Targets",
"targets": [{"refId": "A", "instant": true, "format": "table",
"expr": "up"}],
"transformations": [
{"id": "organize", "options": {
"excludeByName": {"Time": true, "__name__": true},
"renameByName": {"Value": "status"}}}
],
"fieldConfig": {
"defaults": {},
"overrides": [{
"matcher": {"id": "byName", "options": "status"},
"properties": [
{"id": "custom.cellOptions", "value": {"type": "color-background"}},
{"id": "mappings", "value": [{"type": "value", "options": {
"0": {"text": "DOWN", "color": "red"},
"1": {"text": "UP", "color": "green"}}}]}
]}]
},
"options": {"showHeader": true, "footer": {"show": true, "reducer": ["count"]}}
}Remember
- Instant query + Table format gives one row per series
- Cell options (coloured background, gauge, sparkline) are set per column with overrides
- Keep tables short with topk() or LIMIT
Watch out for
- Using a range query in a table and getting a frame picker with hundreds of timestamps per series.