Re: [HACKERS] PANIC: rename from /data/pg_xlog/0000002200000009
I get the feeling that what we will see is the destination
filename already present and the source not, which would suggest
that two backends tried to do the rename concurrently.
Tom,
I just noticed that the rename panic errors like this one:
PANIC: rename from /data/pg_xlog/0003001F to
/data/pg_xlog/0003002C (initialization of log file 3, segment 44)
failed: No such file or directory
come shortly AFTER the following messages
LOG: recycled transaction log file 0003001B
LOG: recycled transaction log file 0003001C
LOG: recycled transaction log file 0003001D
LOG: recycled transaction log file 0003001E
LOG: removing transaction log file 0003001F
LOG: removing transaction log file 00030020
LOG: removing transaction log file 00030021
LOG: removing transaction log file 00030022
So, you can see that 0003001F file was previously deleted by the
logic in MoveOfflineLogs() function.
Now what I can see is that MoveOfflineLogs() does not seem to be
synchronized between backends.
The xlog directory reading loop is not synchronized itself and the caller
code is not synchronized either:
CreateCheckPoint(bool shutdown, bool force)
...
LWLockRelease(ControlFileLock);
/*
* We are now done with critical updates; no need for system panic if
* we have trouble while fooling with offline log segments.
*/
END_CRIT_SECTION();
/*
* Delete offline log files (those no longer needed even for previous
* checkpoint).
*/
if (_logId || _logSeg)
{
PrevLogSeg(_logId, _logSeg);
MoveOfflineLogs(_logId, _logSeg, recptr);
}
...
So is it possible that due to the lack of synchronization, two backends call
MoveOfflineLogs() simultaneously?
For example, first backend has unlinked the log segment file and then the
second one tries to rename the same file because it was returned by
readdir() function before it got deleted by the first beckend.
However, scenario seems to be hard to materialize since it must happen in a
very short timeframe.
The remove and rename log messages look separated in time.
Also, we have a suspicion that the problem happens even with only one client
connected to postgres.
Thanks
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[HACKERS] Help!!! FreeSpaceMap hashtalble out of memory.
Cygwin, 7.3.4 This thing is really KILLING us and our customers. In pgerr.log this always go together: WARNING: ShmemAlloc: out of memory ERROR: FreeSpaceMap hashtable out of memory Theses errors usually take place on INSERT statements like this one: INSERT INTO params (param_id,map_id,param_key,param_value) VALUES (0,858,'MAP_NAME','New Map') params is just a simple table (no triggers or rules involved): CREATE TABLE map_11.params ( param_id int4 NOT NULL, map_id int4 NOT NULL, param_key varchar(1024), param_value text, CONSTRAINT params_pkey PRIMARY KEY (param_id) ) WITH OIDS; The db server machine has 4GB of physical memory and more than half is always available. Number of connection is 64 Number of buffers was increased to 81920 (but this does not help) Is there any parameters that can be configured to increase available shared memory size? Any help is greatly appreciated. attachment: winmail.dat ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] PostgreSQL and Windows
We have a similar question about upcoming Windows native release: Is it going to be multithreaded or one process per connection like on cygwin? -Original Message- From: P.M [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 11, 2003 11:10 PM To: PostGreSQL mailing list Subject: [HACKERS] PostgreSQL and Windows Hi, I would like to know if in the Windows installer version, you still plan to use cygwin to setup PostgreSQL ? If no, how do you setup files and parameters ? Moreover, What are the traps to pay attention when we install PostgreSQL on Windows ? tia, X04001 __ Do you Yahoo!? Yahoo! Calendar - Free online calendar with sync to Outlook(TM). http://calendar.yahoo.com ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [HACKERS] PostgreSQL and Windows
Bruce, thank you for the information. May I ask you one more question? Will it be feasible to run the native Windows version of Postgres in-process (that is in client's process)? Thanks. -Original Message- From: Bruce Momjian [mailto:[EMAIL PROTECTED] Sent: Monday, June 16, 2003 9:37 AM To: Yurgis Baykshtis Cc: PostGreSQL mailing list Subject: Re: [HACKERS] PostgreSQL and Windows Yurgis Baykshtis wrote: We have a similar question about upcoming Windows native release: Is it going to be multithreaded or one process per connection like on cygwin? One connection per process. The only multithreaded Win32 is SRA's commercial product. -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
[HACKERS] Mismatched parentheses when creating a rule with multiple action queries
PostgreSQL 7.3.2. The parser does not seem to like semicolon between action queries: (Mismatched parentheses) So, it makes impossible to create a rule with more than one action query. Or am I missing something? CREATE RULE my_insert_rule AS ON INSERT TO my_view DO INSTEAD ( INSERT INTO my_table1... ; INSERT INTO my_table2... ); The rule with just one action works fine: DO INSTEAD ( INSERT INTO my_table1... ); ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
Re: [HACKERS] Mismatched parentheses when creating a rule with multiple action queries
The problem happens only when running this query from the plpgsql function... So it must be a bug specific to plpgsql parser. -Original Message- From: Yurgis Baykshtis Sent: Wednesday, May 28, 2003 1:07 PM To: [EMAIL PROTECTED] Subject: Mismatched parentheses when creating a rule with multiple action queries PostgreSQL 7.3.2. The parser does not seem to like semicolon between action queries: (Mismatched parentheses) So, it makes impossible to create a rule with more than one action query. Or am I missing something? CREATE RULE my_insert_rule AS ON INSERT TO my_view DO INSTEAD ( INSERT INTO my_table1... ; INSERT INTO my_table2... ); The rule with just one action works fine: DO INSTEAD ( INSERT INTO my_table1... ); ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
