[pgpool-general: 1786] Re: Master-Slave, load bancing and memory cache questions

[Toni Mas]

Hi Tatsuo,

Our configuration are:
master_slave_mode = on
master_slave_sub_mode = 'stream'
load_balance_mode = off

If memory_cache_enabled = on, in PostgreSQL slave backend log display 
internal PgPool queries, for example:


2013-05-28 09:56:05 CEST [3498]:[422] LOG: statement: BEGIN
2013-05-28 09:56:05 CEST [3371]:[659] LOG: execute 
pgpool3347/pgpool3347: SELECT count(*) FROM pg_class AS c, pg_namespace 
AS n WHERE c.relname = 'est_config' AND c.relnamespace = n.oid AND 
n.nspname ~ '^pg_temp_'
2013-05-28 09:56:05 CEST [3484]:[385] LOG: statement: BEGIN
2013-05-28 09:56:05 CEST [3371]:[660] LOG: execute 
pgpool3347/pgpool3347: SELECT count(*) FROM pg_catalog.pg_class AS c 
WHERE c.oid = pgpool_regclass('est_config') AND c.relpersistence = 'u'
2013-05-28 09:56:05 CEST [3473]:[541] LOG: execute 
pgpool3329/pgpool3329: SELECT count(*) FROM pg_class AS c, pg_namespace 
AS n WHERE c.relname = 'est_context' AND c.relnamespace = n.oid AND 
n.nspname ~ '^pg_temp_'
2013-05-28 09:56:05 CEST [3374]:[465] LOG: execute 
pgpool3240/pgpool3240: SELECT count(*) FROM pg_class AS c, pg_namespace 
AS n WHERE c.relname = 'est_capabilities' AND c.relnamespace = n.oid AND 
n.nspname ~ '^pg_temp_'
2013-05-28 09:56:05 CEST [3407]:[430] LOG: execute 
pgpool3337/pgpool3337: SELECT count(*) FROM pg_catalog.pg_class AS c 
WHERE c.oid = pgpool_regclass('est_context') AND c.relpersistence = 'u'
2013-05-28 09:56:05 CEST [3479]:[444] LOG: statement: COMMIT

In otherwise, when memory_cache_enabled = off, same postgresql log only 
show DCL queries, for example:

2013-05-28 09:15:18 CEST [30353]:[514] LOG: statement: SET 
statement_timeout TO DEFAULT
2013-05-28 09:15:18 CEST [30320]:[441] LOG: statement: COMMIT
2013-05-28 09:15:18 CEST [30363]:[475] LOG: statement: BEGIN
2013-05-28 09:15:18 CEST [30353]:[515] LOG: statement: COMMIT
2013-05-28 09:15:18 CEST [30330]:[530] LOG: statement: BEGIN
2013-05-28 09:15:18 CEST [30363]:[476] LOG: statement: SET 
statement_timeout TO DEFAULT
2013-05-28 09:15:18 CEST [30330]:[531] LOG: statement: SET 
statement_timeout TO 120000
2013-05-28 09:15:18 CEST [30363]:[477] LOG: statement: COMMIT
2013-05-28 09:15:18 CEST [30330]:[532] LOG: statement: COMMIT
2013-05-28 09:15:18 CEST [30324]:[472] LOG: statement: BEGIN
2013-05-28 09:15:18 CEST [30324]:[473] LOG: statement: SET 
statement_timeout TO 120000
2013-05-28 09:15:18 CEST [30352]:[606] LOG: statement: BEGIN
2013-05-28 09:15:18 CEST [30352]:[607] LOG: statement: SET 
statement_timeout TO 120000
2013-05-28 09:15:18 CEST [30352]:[608] LOG: statement: COMMIT
2013-05-28 09:15:18 CEST [30319]:[520] LOG: statement: BEGIN
2013-05-28 09:15:18 CEST [30352]:[609] LOG: statement: BEGIN

Why this change of behavior by changing this parameter?



Regards,
Toni

Al 28/05/13 01:15, En/na Tatsuo Ishii ha escrit:
>> Hi,
>>
>> We have experimented an abnormal situation when set on memory
>> cache. We have configured PgPool 3.2.3 version, in master-slave mode
>> and disabled load balancing.
>> I understand reading the documentation, if we have set on master-slave
>> mode, although load balancing parameter was disabled, it has no
>> effect, and Pgpool applied load query balancing. This is true?
>>
>> Agree, the configuration set master-slave mode with stream
>> replication, and load balancing set off. The abnormal situation
>> appears when I have set on or off memory cache. If we have disabled
>> memory cache, Pgpool no applied load query balancing. In otherwise,
>> when memory cache is enabled, PgPool applied load query
>> balancing. This is normal situation, or there may be an bug?
> Are you saying that "load_balance_mode = off" does not take effect if
> "memory_cache_enabled = on"? Did not reproduce here. Can you please
> show us more details.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp


-- 
Toni Mas
Universitat de les Illes Balears
Ctra. Valldemossa Km 7,5
971 17 27 21

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