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Track some pg_stat metrics

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Hopefully this'll help track database things better.
This commit is contained in:
Christopher Baines 2020-10-01 21:43:41 +01:00
parent 404f39a9ee
commit 7f49756bac
2 changed files with 82 additions and 2 deletions
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46
guix-data-service/metrics.scm
View file

@ -18,7 +18,8 @@
(define-module (guix-data-service metrics)
#:use-module (ice-9 match)
#:use-module (squee)
#:export (fetch-high-level-table-size-metrics))
#:export (fetch-high-level-table-size-metrics
fetch-pg-stat-user-tables-metrics))
(define (fetch-high-level-table-size-metrics conn)
;; Adapted from https://wiki.postgresql.org/wiki/Disk_Usage
@ -77,3 +78,46 @@ FROM (
(or (string->number index-bytes) 0)
(or (string->number toast-bytes) 0))))
(exec-query conn query)))
(define (fetch-pg-stat-user-tables-metrics conn)
(define query
"
SELECT relname, seq_scan, seq_tup_read,
idx_scan, idx_tup_fetch,
n_tup_ins, n_tup_upd, n_tup_del, n_tup_hot_upd,
n_live_tup, n_dead_tup, n_mod_since_analyze,
COALESCE(extract(epoch from last_vacuum), 0),
COALESCE(extract(epoch from last_autovacuum), 0),
COALESCE(extract(epoch from last_analyze), 0),
COALESCE(extract(epoch from last_autoanalyze), 0),
vacuum_count, autovacuum_count, analyze_count, autoanalyze_count
FROM pg_stat_user_tables")
(map (match-lambda
((relname seq-scan seq-tup-read
idx-scan idx-tup-fetch
n-tup-ins n-tup-upd n-tup-del n-tup-hot-upd
n-live-tup n-dead-tup n-mod-since-analyze
last-vacuum last-autovacuum last-analyze last-autoanalyze
vacuum-count autovacuum-count analyze-count autoanalyze-count)
`((name . ,relname)
(seq-scan . ,seq-scan)
(seq-tup-read . ,seq-tup-read)
(idx-scan . ,idx-scan)
(idx-tup-fetch . ,idx-tup-fetch)
(n-tup-ins . ,n-tup-ins)
(n-tup-upd . ,n-tup-upd)
(n-tup-del . ,n-tup-del)
(n-tup-hot-upd . ,n-tup-hot-upd)
(n-live-tup . ,n-live-tup)
(n-dead-tup . ,n-dead-tup)
(n-mod-since-analyze . ,n-mod-since-analyze)
(last-vacuum . ,last-vacuum)
(last-autovacuum . ,last-autovacuum)
(last-analyze . ,last-analyze)
(last-autoanalyze . ,last-autoanalyze)
(vacuum-count . ,vacuum-count)
(autovacuum-count . ,autovacuum-count)
(analyze-count . ,analyze-count)
(autoanalyze-count . ,autoanalyze-count))))
(exec-query conn query)))

38
guix-data-service/web/controller.scm
View file

@ -21,6 +21,7 @@
#:use-module (ice-9 vlist)
#:use-module (ice-9 pretty-print)
#:use-module (ice-9 textual-ports)
#:use-module (ice-9 string-fun)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
@ -106,7 +107,28 @@
#:labels '(name)))
(table-toast-bytes-metric (make-gauge-metric registry
"table_toast_bytes"
#:labels '(name))))
#:labels '(name)))
(pg-stat-fields '(seq-scan seq-tup-read idx-scan idx-tup-fetch
n-tup-ins n-tup-upd n-tup-del
n-tup-hot-upd n-live-tup n-dead-tup
n-mod-since-analyze last-vacuum
last-autovacuum last-analyze last-autoanalyze
vacuum-count autovacuum-count
analyze-count autoanalyze-count))
(pg-stat-metrics (map (lambda (field)
(cons
field
(make-gauge-metric
registry
(string-append "pg_stat_"
(string-replace-substring
(symbol->string field)
"-"
"_"))
#:labels '(name))))
pg-stat-fields)))
(lambda (conn)
(let ((metric-values (fetch-high-level-table-size-metrics conn)))
(for-each (match-lambda
@ -129,6 +151,20 @@
(metric-set revisions-count-metric
(count-guix-revisions conn))
(map (lambda (field-values)
(let ((name (assq-ref field-values 'name)))
(for-each
(match-lambda
(('name . _) #f)
((field . value)
(let ((metric (or (assq-ref pg-stat-metrics field)
(error field))))
(metric-set metric
value
#:label-values `((name . ,name))))))
field-values)))
(fetch-pg-stat-user-tables-metrics conn))
(for-each (match-lambda
((repository-label completed count)
(metric-set