A lot of work working on postgresql and today was another day of performance and fixing issues, eventually let add this set of scripts giving by one of my peers (Thanks Troy), now that I have them is time to shared with the world.
Cheers..
Is this a master or read only server I'm on now? Can it accept writes?
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select pg_is_in_recovery();
or, just try to create a database. You will fail if it's a standby.
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Check server activity:
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select * from pg_stat_activity;
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2 queries for database blocking and locking ( to be run on master node )
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SELECT blocked_locks.pid AS blocked_pid,
blocked_activity.usename AS blocked_user,
blocking_locks.pid AS blocking_pid,
blocking_activity.usename AS blocking_user,
blocked_activity.query AS blocked_statement,
blocking_activity.query AS current_statement_in_blocking_process
FROM pg_catalog.pg_locks blocked_locks
JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid
JOIN pg_catalog.pg_locks blocking_locks
ON blocking_locks.locktype = blocked_locks.locktype
AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
AND blocking_locks.pid != blocked_locks.pid
JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
WHERE NOT blocked_locks.GRANTED;
# There's also:
SELECT
waiting.locktype AS waiting_locktype,
waiting.relation::regclass AS waiting_table,
waiting_stm.query AS waiting_query,
waiting.mode AS waiting_mode,
waiting.pid AS waiting_pid,
other.locktype AS other_locktype,
other.relation::regclass AS other_table,
other_stm.query AS other_query,
other.mode AS other_mode,
other.pid AS other_pid,
other.GRANTED AS other_granted
FROM
pg_catalog.pg_locks AS waiting
JOIN
pg_catalog.pg_stat_activity AS waiting_stm
ON (waiting_stm.pid = waiting.pid)
JOIN
pg_catalog.pg_locks AS other
ON ((waiting."database" = other."database"
AND waiting.relation = other.relation
)OR waiting.transactionid = other.transactionid)
JOIN pg_catalog.pg_stat_activity AS other_stm
ON (other_stm.pid = other.pid)
WHERE NOT waiting.GRANTED
AND waiting.pid <> other.pid;
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# Recursive view of blocking
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WITH RECURSIVE
c(requested, CURRENT) AS
( VALUES
('AccessShareLock'::text, 'AccessExclusiveLock'::text),
('RowShareLock'::text, 'ExclusiveLock'::text),
('RowShareLock'::text, 'AccessExclusiveLock'::text),
('RowExclusiveLock'::text, 'ShareLock'::text),
('RowExclusiveLock'::text, 'ShareRowExclusiveLock'::text),
('RowExclusiveLock'::text, 'ExclusiveLock'::text),
('RowExclusiveLock'::text, 'AccessExclusiveLock'::text),
('ShareUpdateExclusiveLock'::text, 'ShareUpdateExclusiveLock'::text),
('ShareUpdateExclusiveLock'::text, 'ShareLock'::text),
('ShareUpdateExclusiveLock'::text, 'ShareRowExclusiveLock'::text),
('ShareUpdateExclusiveLock'::text, 'ExclusiveLock'::text),
('ShareUpdateExclusiveLock'::text, 'AccessExclusiveLock'::text),
('ShareLock'::text, 'RowExclusiveLock'::text),
('ShareLock'::text, 'ShareUpdateExclusiveLock'::text),
('ShareLock'::text, 'ShareRowExclusiveLock'::text),
('ShareLock'::text, 'ExclusiveLock'::text),
('ShareLock'::text, 'AccessExclusiveLock'::text),
('ShareRowExclusiveLock'::text, 'RowExclusiveLock'::text),
('ShareRowExclusiveLock'::text, 'ShareUpdateExclusiveLock'::text),
('ShareRowExclusiveLock'::text, 'ShareLock'::text),
('ShareRowExclusiveLock'::text, 'ShareRowExclusiveLock'::text),
('ShareRowExclusiveLock'::text, 'ExclusiveLock'::text),
('ShareRowExclusiveLock'::text, 'AccessExclusiveLock'::text),
('ExclusiveLock'::text, 'RowShareLock'::text),
('ExclusiveLock'::text, 'RowExclusiveLock'::text),
('ExclusiveLock'::text, 'ShareUpdateExclusiveLock'::text),
('ExclusiveLock'::text, 'ShareLock'::text),
('ExclusiveLock'::text, 'ShareRowExclusiveLock'::text),
('ExclusiveLock'::text, 'ExclusiveLock'::text),
('ExclusiveLock'::text, 'AccessExclusiveLock'::text),
('AccessExclusiveLock'::text, 'AccessShareLock'::text),
('AccessExclusiveLock'::text, 'RowShareLock'::text),
('AccessExclusiveLock'::text, 'RowExclusiveLock'::text),
('AccessExclusiveLock'::text, 'ShareUpdateExclusiveLock'::text),
('AccessExclusiveLock'::text, 'ShareLock'::text),
('AccessExclusiveLock'::text, 'ShareRowExclusiveLock'::text),
('AccessExclusiveLock'::text, 'ExclusiveLock'::text),
('AccessExclusiveLock'::text, 'AccessExclusiveLock'::text)
),
l AS
(
SELECT
(locktype,DATABASE,relation::regclass::text,page,tuple,virtualxid,transactionid,classid,objid,objsubid) AS target,
virtualtransaction,
pid,
mode,
GRANTED
FROM pg_catalog.pg_locks
),
t AS
(
SELECT
blocker.target AS blocker_target,
blocker.pid AS blocker_pid,
blocker.mode AS blocker_mode,
blocked.target AS target,
blocked.pid AS pid,
blocked.mode AS mode
FROM l blocker
JOIN l blocked
ON ( NOT blocked.GRANTED
AND blocker.GRANTED
AND blocked.pid != blocker.pid
AND blocked.target IS NOT DISTINCT FROM blocker.target)
JOIN c ON (c.requested = blocked.mode AND c.CURRENT = blocker.mode)
),
r AS
(
SELECT
blocker_target,
blocker_pid,
blocker_mode,
'1'::INT AS depth,
target,
pid,
mode,
blocker_pid::text || ',' || pid::text AS seq
FROM t
UNION ALL
SELECT
blocker.blocker_target,
blocker.blocker_pid,
blocker.blocker_mode,
blocker.depth + 1,
blocked.target,
blocked.pid,
blocked.mode,
blocker.seq || ',' || blocked.pid::text
FROM r blocker
JOIN t blocked
ON (blocked.blocker_pid = blocker.pid)
WHERE blocker.depth < 1000
)
SELECT * FROM r
ORDER BY seq;
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Need more info that the logs aren't giving you? Adjust the postgresql.conf file to allow verbose logging.
You'll need to load the config changes by "pg_ctl reload", then check the logs to ensure they were loaded.
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log_duration = on|off
log_lock_waits = on|off
log_min_duration_statement = Xs (can be adjusted, in seconds)
deadlock_timeout = Xs (can be adjusted, in seconds)
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pg_buffercache (create extension pg_buffercache;) to create the extension if it isn't already there.
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SELECT c.relname, count(*) AS buffers
FROM pg_buffercache b INNER JOIN pg_class c
ON b.relfilenode = pg_relation_filenode(c.oid) AND
b.reldatabase IN (0, (SELECT oid FROM pg_database
WHERE datname = current_database()))
GROUP BY c.relname
ORDER BY 2 DESC
LIMIT 100;
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postgres cache hit ratio (create extension pg_buffercache;) to create the extension if it isn't already there.
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SELECT sum(heap_blks_read) as heap_read,
sum(heap_blks_hit) as heap_hit,
sum(heap_blks_hit) / (sum(heap_blks_hit) + sum(heap_blks_read)) as ratio
FROM pg_statio_user_tables;
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postgres index cache hit ratio (create extension pg_buffercache;) to create the extension if it isn't already there.
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SELECT sum(idx_blks_read) as idx_read,
sum(idx_blks_hit) as idx_hit,
(sum(idx_blks_hit) - sum(idx_blks_read)) / sum(idx_blks_hit) as ratio
FROM pg_statio_user_indexes;
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Is postgres using ssl for its connections? Let's see:
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select datname, usename, client_addr, ssl, cipher
from pg_stat_activity
join pg_stat_ssl on pg_stat_activity.pid=pg_stat_ssl.pid;
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Table and index stats
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with table_stats as (
select psut.relname,
psut.n_live_tup,
1.0 * psut.idx_scan / greatest(1, psut.seq_scan + psut.idx_scan) as index_use_ratio
from pg_stat_user_tables psut
order by psut.n_live_tup desc
),
table_io as (
select psiut.relname,
sum(psiut.heap_blks_read) as table_page_read,
sum(psiut.heap_blks_hit) as table_page_hit,
sum(psiut.heap_blks_hit) / greatest(1, sum(psiut.heap_blks_hit) + sum(psiut.heap_blks_read)) as table_hit_ratio
from pg_statio_user_tables psiut
group by psiut.relname
order by table_page_read desc
),
index_io as (
select psiui.relname,
psiui.indexrelname,
sum(psiui.idx_blks_read) as idx_page_read,
sum(psiui.idx_blks_hit) as idx_page_hit,
1.0 * sum(psiui.idx_blks_hit) / greatest(1.0, sum(psiui.idx_blks_hit) + sum(psiui.idx_blks_read)) as idx_hit_ratio
from pg_statio_user_indexes psiui
group by psiui.relname, psiui.indexrelname
order by sum(psiui.idx_blks_read) desc
)
select ts.relname, ts.n_live_tup, ts.index_use_ratio,
ti.table_page_read, ti.table_page_hit, ti.table_hit_ratio,
ii.indexrelname, ii.idx_page_read, ii.idx_page_hit, ii.idx_hit_ratio
from table_stats ts
left outer join table_io ti
on ti.relname = ts.relname
left outer join index_io ii
on ii.relname = ts.relname
order by ti.table_page_read desc, ii.idx_page_read desc
;
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Table & Index Bloat query (from check_postgres script)
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SELECT
current_database(), schemaname, tablename, /*reltuples::bigint, relpages::bigint, otta,*/
ROUND((CASE WHEN otta=0 THEN 0.0 ELSE sml.relpages::FLOAT/otta END)::NUMERIC,1) AS tbloat,
CASE WHEN relpages < otta THEN 0 ELSE bs*(sml.relpages-otta)::BIGINT END AS wastedbytes,
iname, /*ituples::bigint, ipages::bigint, iotta,*/
ROUND((CASE WHEN iotta=0 OR ipages=0 THEN 0.0 ELSE ipages::FLOAT/iotta END)::NUMERIC,1) AS ibloat,
CASE WHEN ipages < iotta THEN 0 ELSE bs*(ipages-iotta) END AS wastedibytes
FROM (
SELECT
schemaname, tablename, cc.reltuples, cc.relpages, bs,
CEIL((cc.reltuples*((datahdr+ma-
(CASE WHEN datahdr%ma=0 THEN ma ELSE datahdr%ma END))+nullhdr2+4))/(bs-20::FLOAT)) AS otta,
COALESCE(c2.relname,'?') AS iname, COALESCE(c2.reltuples,0) AS ituples, COALESCE(c2.relpages,0) AS ipages,
COALESCE(CEIL((c2.reltuples*(datahdr-12))/(bs-20::FLOAT)),0) AS iotta -- very rough approximation, assumes all cols
FROM (
SELECT
ma,bs,schemaname,tablename,
(datawidth+(hdr+ma-(CASE WHEN hdr%ma=0 THEN ma ELSE hdr%ma END)))::NUMERIC AS datahdr,
(maxfracsum*(nullhdr+ma-(CASE WHEN nullhdr%ma=0 THEN ma ELSE nullhdr%ma END))) AS nullhdr2
FROM (
SELECT
schemaname, tablename, hdr, ma, bs,
SUM((1-null_frac)*avg_width) AS datawidth,
MAX(null_frac) AS maxfracsum,
hdr+(
SELECT 1+COUNT(*)/8
FROM pg_stats s2
WHERE null_frac<>0 AND s2.schemaname = s.schemaname AND s2.tablename = s.tablename
) AS nullhdr
FROM pg_stats s, (
SELECT
(SELECT current_setting('block_size')::NUMERIC) AS bs,
CASE WHEN SUBSTRING(v,12,3) IN ('8.0','8.1','8.2') THEN 27 ELSE 23 END AS hdr,
CASE WHEN v ~ 'mingw32' THEN 8 ELSE 4 END AS ma
FROM (SELECT version() AS v) AS foo
) AS constants
GROUP BY 1,2,3,4,5
) AS foo
) AS rs
JOIN pg_class cc ON cc.relname = rs.tablename
JOIN pg_namespace nn ON cc.relnamespace = nn.oid AND nn.nspname = rs.schemaname AND nn.nspname <> 'information_schema'
LEFT JOIN pg_index i ON indrelid = cc.oid
LEFT JOIN pg_class c2 ON c2.oid = i.indexrelid
) AS sml
ORDER BY wastedbytes DESC;
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relations buffered in database share buffer
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select c.relname,pg_size_pretty(count(*) * 8192) as buffered,
round(100.0 * count(*) / (
select setting from pg_settings
where name='shared_buffers')::integer,1)
as buffer_percent,
round(100.0*count(*)*8192 / pg_table_size(c.oid),1) as percent_of_relation
from pg_class c inner join pg_buffercache b on b.relfilenode = c.relfilenode inner
join pg_database d on ( b.reldatabase =d.oid and d.datname =current_database())
group by c.oid,c.relname order by 3 desc limit 100;
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disk usage
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select nspname,relname,pg_size_pretty(pg_relation_size(c.oid)) as "size"
from pg_class c left join pg_namespace n on ( n.oid=c.relnamespace)
where nspname not in ('pg_catalog','information_schema')
order by pg_relation_size(c.oid) desc limit 30;
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