[firebird-support] Re: [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread thetr...@yahoo.com [firebird-support] 
Hey Thomas,
thanks for your extensive reply.
Unfortunatly we'r still bound to some old 32bit UDF functionality which we 
can't get in 64bit. 
I think you know about the use of SuperClassic with 32bit Server - 2GB RAM 
Limit :)
It's not impossible, but also not really a fast route we can go. But for sure 
again a reason to talk about moving the switch to 2.5.

We did ran some some disk IO benchmarks (with AS SSD) today, and in times of 
SSD kinda depressing :D
The thing is, sure this numbers look really low. But the system never uses it. 
The monitoring of the SAN show's that this load's are never used. The 
Single-4k-read is worring me, but i lean towards that our 500 proceses are more 
like the 64-thread test. But even then, we only messured 100 Iops reading on 
livesystem.

Sequential Read speed: ~ 450 MB / s
Sequential Write speed: ~500 MB / s
4k read: 196 Iops
4k write: 1376 Iops
4k-64 thread read: 15945 Iops
4k-64 thread write: 7361 Iops


 Garbage Info still needs to be collected.
But first signs show that this indeed could be a potential problem.
From Sintatica, every 20 Minutes a Peak in GC for ~15.000 transactions. This 
get's fixed by the server in the relative small amount of time (i think < 1 
minute), since it's really only a single peak in the graph everytime.
When the GC stop increasing and the server starts to collect it, we see an 
increase of concurrent running transactions (= transactions are longer open and 
processed slower).

We don't have data from the live system yet to see if this behaviour kind of 
"snowballs" when there is really high load on the server.

Best Regards,

---In firebird-support@yahoogroups.com,  wrote :

 Hi Patrick,
 
 > Hi Thomas, nice to get a response from you. We already met in ~2010 in Linz 
 > at
 > your office :)
 > (ex. SEM GmbH, later Playmonitor GmbH)
 
 I know. XING (Big Brother) is watching you. Nice to see that you are still 
running with Firebird. ;-)
 
 
 > First, sorry for posting a mixed state of informations. The config settings i
 > postet are the current settings.
 > But the Lock-Table-Header was from last saturday (day of total system crash) 
 > -
 > we changed Hash Slot Value since than, but it didn't work. New Table looks
 > like:
 > 
 > 
 > LOCK_HEADER BLOCK
 > Version: 16, Active owner: 0, Length: 134247728, Used: 55790260
 > Semmask: 0x0, Flags: 0x0001
 > Enqs: 1806423519, Converts: 4553851, Rejects: 5134185, Blocks: 56585419
 > Deadlock scans: 82, Deadlocks: 0, Scan interval: 10
 > Acquires: 2058846891, Acquire blocks: 321584126, Spin count: 0
 > Mutex wait: 15.6%
 > Hash slots: 20011, Hash lengths (min/avg/max): 0/ 7/ 18
 > Remove node: 0, Insert queue: 0, Insert prior: 0
 > Owners (297): forward: 385160, backward: 38086352
 > Free owners (43): forward: 52978748, backward: 20505128
 > Free locks (41802): forward: 180712, backward: 3620136
 > Free requests (-1097572396): forward: 46948676, backward: 13681252
 > Lock Ordering: Enabled
 > 
 > 
 > The Min/Avg/Max hash lengths look better now, but as you mentioned the Mutex
 > wait is worring us too.
 > We have 2 direct questions about that.
 > 
 > 
 > 1) What are the negative effects of increasing Hash-Slots (too high)?
 
 It somehow defines the initial size of a hash table which is used for lock(ed) 
object lookup by a key (= hash value), ideally with constant O(1) run-time 
complexity. If the hash table is too small, due to a too small value for hash 
slots, it starts to degenerate into a linked/linear list per hash slot. Worst 
case resulting in O(n) complexity for lookups. The above 20011 setting shows an 
AVG hash length which looks fine.
 
 As you might know, Classic having a dedicated process per connection model 
somehow needs a (global) mechanism to synchronize/protect shared data 
structures across these processes via IPC. This is what the lock manager and 
the lock table is used for.
 
 > 2) As far as we know, we can't influence Mutex wait directly (it's just
 > informational). But do you think that's the reason the underlying hardware is
 > not utilized?
 
 I don't think you are disk IO bound. Means, I'm not convinced that faster IO 
will help. Somehow backed by the high mutex wait. Under normal operations you 
see 100-500 IOPS with some room for further increase as shown in the 1700 IOPS 
backup use case. Don't know how random disk IO is in this two scenarios. Any 
chance to run some sort of disk IO benchmarks or do you already know your upper 
limits for your SAN IOPS wise?
 
 > 
 > 
 > We do consider to upgrade to 2.5, but had our eyes on FB 3 over the last 
 > year,
 > waiting for it to get ready.
 > With 2.5.x we tested around a long time now, but never found a real reason to
 > upgrade - since it's a reasonable amount of work for us. When you say it
 > improves the lock contention, this sound pretty good. But again the question,
 > do you think lock contention is limiting our system?
 
 Dmitry, Vlad etc. will correct me (in case he is following the thread), but I

[firebird-support] Re: [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread thetr...@yahoo.com [firebird-support] 

 Hey Alexey,
thanks you for our input. I think what you say is correct, and we reviewed our 
disk setup again.
We are utilizing mechnical discs so it's kinda hard to compare SSD performance 
to them.
But they should provide enought IOPS for our load.

Unfortunatly we can't just switch to a single SSD, since we would loose 
replication and failover systems the SAN provides which is a critical demand 
for us. I'm afraid for now we have to stick with it, until we have some facts 
to proof that the SAN Setup is our limiting factor. And data is not should that 
for me currently.

On a sidenode, we do own a server with SSD setup, but in tests we couldn't get 
a noticable performance gain through increasement of IOs this way. (tests was 
generic and not real world load unfortunatly)

Best Regards,
Patrick

---In firebird-support@yahoogroups.com,  wrote :

 Hi Patrick,
 
 If you say that problem occurred recently, I would suggest you to check SAN 
disks health.
 
 However, these values
 >Average
 system IOPS under load read: 100
 >Average system IOPS under load write: 550
 >Backup Restore IOPS read: 1700
 >Backup Restore IOPS write: 250 are really, really low. 
 1700 IOPS for the database with 4k page means 6.8Mb/sec (in case of random 
reads).
 
 I suggest to install a single SSD drive and check how it will work.
 SSD IOPS looks like
   Random Read 4KB (QD=32) :   283.050 MB/s [ 69104.0 IOPS]
   Random Write 4KB (QD=32) :   213.837 MB/s [ 52206.2 IOPS]
 
 
 From our optimization practice we found that if you need to optimize only the 
single instance of the database, the most cost effective way is to upgrade to 
SSD first, and only then fix other problems.
 
 Regards,
 Alexey Kovyazin
 IBSurgeon HQbird www.ib-aid.com http://www.ib-aid.com
 
 
 

   hi,
 recently we had some strange performance issues with our Firebird DB server.
 On high load, our server started to slow down. Select and update SQL query 
times did go up by more than 500% on average,
 but reaching unreasonable high execution times at worst case. (several minutes 
instead of < 1sec)
 

 OIT/OAT/Next Transaction statistics was within 1000 the hole time
 We were not able to messure any hardware limiting factor. Indeed, this system 
was running with only 8 cores at about 70% CPU usage on max. load.
 We decided that this may be our problem since we experienced a similar problem 
at about 80% CPU load in the past.
 So we upgraded the hardware. As expected, the CPU-load dropped to ~35% usage 
on max. load scenario.
 But this did not solve the problem.
 Same story for the harddisk system. The usage is not even near it's max 
capacity.
 

 We also can't see any impact on the harddisk.
 We'r kind of stuck with our ideas, because we have no idea what could be a 
potential bottleneck to the system.
 Since the hardware doesn't show a limit, there have to be anything else - most 
likely firebird engine related that's limiting our system.
 We would be very grateful if anyone can give us hints where we can search 
further.
 Or someone has similar experiences to share with us.
 

 

 Operating System: Windows Server 2003
 Firebird: 2.1.5 Classic
 Dedicated database server (VMWare)
 

 CPU: 16 cores, each 2.4 GHz
 RAM: 32 GB
 About 14GB are used from OS and firebird processes under max load.
 
 HDD: SAN Storage System
 

 Average system IOPS under load read: 100
 Average system IOPS under load write: 550
 Backup Restore IOPS read: 1700
 Backup Restore IOPS write: 250
 SAN IPOS Limit (max): 3000
 

 Firebird Config Settings, based on defaults
 DefaultDbCachePages = 1024
 LockMemSize = 134247728
 LockHashSlots = 20011
 
 Database
 size: about 45 GB
 450 to 550 concurrent connections
 Daily average of 65 transactions / second (peak should be higher)
 

 FB_LOCK_PRINT (without any params) while system was slowing down (~4 days 
uptime).
 I have to note, Firebird was not able to print the complete output (stats was 
not cropped by me)
 

 LOCK_HEADER BLOCK
 Version: 16, Active owner:  0, Length: 134247728, Used: 82169316
 Semmask: 0x0, Flags: 0x0001
 Enqs: 4211018659, Converts: 10050437, Rejects: 9115488, Blocks: 105409192
 Deadlock scans:   1049, Deadlocks:  0, Scan interval:  10
 Acquires: 4723416170, Acquire blocks: 640857597, Spin count:   0
 Mutex wait: 13.6%
 Hash slots: 15077, Hash lengths (min/avg/max):3/  12/  25
 Remove node:  0, Insert queue: 36, Insert prior: 74815332
 Owners (456): forward: 131316, backward: 14899392
 Free owners (9): forward: 39711576, backward: 49867232
 Free locks (42409): forward: 65924212, backward: 23319052
 

 
 With best Regards,
 

 Patrick Friessnegg
 Synesc GmbH

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread thetr...@yahoo.com [firebird-support] 
Hey,
not sure how you can survive with superserver :)
I can't see that working with our kind of load (realtime-data-processing, 
reports, mostly write IOPS)
It's a long time ago (Fb 1.5) since we used superserver but we didn't have the 
best time with it back then.

But currently this is not about switching the server-version. More about 
undestanding why the server is not using the provided hardware :)

Also it reads kinda strange if you talk about high load, but always have low 
cpu usage :)
 

---In firebird-support@yahoogroups.com,  wrote :

 Hi,
  
 just curious – why not superserver?
 I do not know what your system do and if it is cpu intensive –
 but i always use superserver because of big cache and this is for me biggest 
speed up.
 I use superserver in environment with ~400 connections (near constant) and 
high load without problem.
  
 PS. i wait for FB3.0 and all my servers will gain another speed up because of 
multicore use.
 But i have always low cpu usage also in high load system – and i do not know 
why you can got 80% CPU load – maybe this is some issue or some “weekness” of 
classic?
  
 regards,
 Karol Bieniaszewski
  
 From: mailto:firebird-support@yahoogroups.com 
mailto:firebird-support@yahoogroups.com
 Sent: Monday, April 11, 2016 2:55 PM
 To: firebird-support@yahoogroups.com mailto:firebird-support@yahoogroups.com
 Subject: [firebird-support] [FB 2.1] Firebird engine seems to slow down on 
high load without utilizing hardware


  

   
 hi,
 recently we had some strange performance issues with our Firebird DB server.
 On high load, our server started to slow down. Select and update SQL query 
times did go up by more than 500% on average,
 but reaching unreasonable high execution times at worst case. (several minutes 
instead of < 1sec)
  
 OIT/OAT/Next Transaction statistics was within 1000 the hole time
 We were not able to messure any hardware limiting factor. Indeed, this system 
was running with only 8 cores at about 70% CPU usage on max. load.
 We decided that this may be our problem since we experienced a similar problem 
at about 80% CPU load in the past.
 So we upgraded the hardware. As expected, the CPU-load dropped to ~35% usage 
on max. load scenario.
 But this did not solve the problem.
 Same story for the harddisk system. The usage is not even near it's max 
capacity.
  
 We also can't see any impact on the harddisk.
< p>We'r kind of stuck with our ideas, because we have no idea what could be a 
potential bottleneck to the system. Since the hardware doesn't show a limit, 
there have to be anything else - most likely firebird engine related that's 
limiting our system.
 We would be very grateful if anyone can give us hints where we can search 
further.
 Or someone has similar experiences to share with us.
  
  
 Operating System: Windows Server 2003
 Firebird: 2.1.5 Classic
 Dedicated database server (VMWare)
  
 CPU: 16 cores, each 2.4 GHz
 RAM: 32 GB
 About 14GB are used from OS and firebird processes under max load.
 
 HDD: SAN Storage System
  
 Average system IOPS under load read: 100
 Average system IOPS under load write: 550
 Backup Restore IOPS read: 1700
 Backup Restore IOPS write: 250
 SAN IPOS Limit (max): 3000
  
 Firebird Config Settings, based on defaults
 DefaultDbCachePages = 1024
 LockMemSize = 134247728
 LockHashSlots = 20011
 
 Database
 size: about 45 GB
 450 to 550 concurrent connections
 Daily average of 65 transactions / second (peak should be higher)
  
 FB_LOCK_PRINT (without any params) while system was slowing down (~4 days 
uptime).
 I have to note, Firebird was not able to print the complete output (stats was 
not cropped by me)
  
 LOCK_HEADER BLOCK
 Version: 16, Active owner:  0, Length: 134247728, Used: 82169316
 Semmask: 0x0, Flags: 0x0001
 Enqs: 4211018659, Converts: 10050437, Rejects: 9115488, Blocks: 105409192
 Deadlock scans:   1049, Deadlocks:  0, Scan interval:  10
 Acquires: 4723416170, A cquire blocks: 640857597, Spin count:   0
 Mutex wait: 13.6%
 Hash slots: 15077, Hash lengths (min/avg/max):3/  12/  25
 Remove node:  0, Insert queue: 36, Insert prior: 74815332
 Owners (456): forward: 131316, backward: 14899392
 Free owners (9): forward: 39711576, backward: 49867232
 Free locks (42409): forward: 65924212, backward: 23319052
  
 
 With best Regards,
  
 Patrick Friessnegg
 Synesc GmbH

Re: [firebird-support] Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread Thomas Steinmaurer t...@iblogmanager.com [firebird-support] 
> There is 77GB free out of 148GB at the minute and it has restored 9GB so
> far, final size ~33GB so on the surface looks adequate unless very large
> temp files are created when the indexes are reactivated?

Yes. This may happen, depending on the index size. Are you sure that 
temp space is actually pointing to the disk with 77G free space?

* What is the value for the TEMP/TMP environment variable (in case you 
are on Windows)?
* Any manual changes for TempDirectories in firebird.conf?


-- 
With regards,
Thomas Steinmaurer
http://www.upscene.com/

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.

Re: [firebird-support] Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread tomconl...@gmail.com [firebird-support] 
There is 77GB free out of 148GB at the minute and it has restored 9GB so far, 
final size ~33GB so on the surface looks adequate unless very large temp files 
are created when the indexes are reactivated?

Re: [firebird-support] Re: Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread Dimitry Sibiryakov s...@ibphoenix.com [firebird-support] 
12.04.2016 23:04, tomconl...@gmail.com [firebird-support] wrote:
> It's a production database but this restore is for a side-project (email 
> logging). I
> clearly need to get to the root of the problem.

   You run out of temp space. Buy new HDD.

-- 
   WBR, SD.






++

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[firebird-support] Re: Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread tomconl...@gmail.com [firebird-support] 
I'm now trying to restore it with "ignore validity constraints" off in 
flamerobin. 

 It's a production database but this restore is for a side-project (email 
logging). I clearly need to get to the root of the problem.  
 

 The offending index is added to using a generated integer within a trigger so 
it is very odd to get this error. The system has been up for 6-7 years now, 
20-25 users.

Re: [firebird-support] Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread Thomas Steinmaurer t...@iblogmanager.com [firebird-support] 
Hi!

> gbak:activating and creating deferred index K_MERCURY_EMAIL
>
> gbak:cannot commit index K_MERCURY_EMAIL
>
> gbak: ERROR:operating system directive CreateFile failed

Any chance that you are running out of disk where your TEMP directory is 
located?


-- 
With regards,
Thomas Steinmaurer
http://www.upscene.com/

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.



> gbak: ERROR:The system cannot find the path specified.
>
> Database restore canceled 21:17:19 due to IBPP exception:
>
>
> *** IBPP::SQLException ***
>
> Context: ServiceImpl::Wait
>
> Message: isc_service_query failed
>
>
> SQL Message : -901
>
> Unsuccessful execution caused by system error that does not preclude
> successful execution of subsequent statements
>
>
> Engine Code: 335544342
>
> Engine Message :
>
> action cancelled by trigger (3) to preserve data integrity
>
> Cannot deactivate index used by a PRIMARY/UNIQUE constraint
>
>
>
>
>

[firebird-support] Cannot restore 32GB DB - fails at end, unusable. Any ideas please.

2016-04-12 Thread tomconl...@gmail.com [firebird-support] 
gbak:activating and creating deferred index K_MERCURY_EMAIL 
 gbak:cannot commit index K_MERCURY_EMAIL 
 gbak: ERROR:operating system directive CreateFile failed 
 gbak: ERROR:The system cannot find the path specified.  
 Database restore canceled 21:17:19 due to IBPP exception:
 

 *** IBPP::SQLException ***
 Context: ServiceImpl::Wait
 Message: isc_service_query failed
 

 SQL Message : -901
 Unsuccessful execution caused by system error that does not preclude 
successful execution of subsequent statements
 

 Engine Code: 335544342
 Engine Message :
 action cancelled by trigger (3) to preserve data integrity
 
 Cannot deactivate index used by a PRIMARY/UNIQUE constraint

Re: [firebird-support] Re: Composite index - issue or not existing feature?

2016-04-12 Thread liviusliv...@poczta.onet.pl [firebird-support] 
Hi Ann,
This is the crux of the matter
“Index entries for the old and new versions of a record all contain the DBKey 
of the primary (newest) record version.  When doing an indexed lookup,
Firebird walks backward through the record versions until it finds one that
the current transaction can see, then check whether the key values in that
record version match the lookup values.”

thanks you again
now i am ready to digg into FB source code – sadly i do not like C++ 

regards,
Karol Bieniaszewski

[Non-text portions of this message have been removed]

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread liviusliv...@poczta.onet.pl [firebird-support] 
Hi,

just curious – why not superserver?
I do not know what your system do and if it is cpu intensive – 
but i always use superserver because of big cache and this is for me biggest 
speed up.
I use superserver in environment with ~400 connections (near constant) and high 
load without problem.

PS. i wait for FB3.0 and all my servers will gain another speed up because of 
multicore use.
But i have always low cpu usage also in high load system – and i do not know 
why you can got 80% CPU load – maybe this is some issue or some “weekness” of 
classic?

regards,
Karol Bieniaszewski

From: mailto:firebird-support@yahoogroups.com 
Sent: Monday, April 11, 2016 2:55 PM
To: firebird-support@yahoogroups.com 
Subject: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high 
load without utilizing hardware

  

hi,

recently we had some strange performance issues with our Firebird DB server.

On high load, our server started to slow down. Select and update SQL query 
times did go up by more than 500% on average,

but reaching unreasonable high execution times at worst case. (several minutes 
instead of < 1sec)



OIT/OAT/Next Transaction statistics was within 1000 the hole time

We were not able to messure any hardware limiting factor. Indeed, this system 
was running with only 8 cores at about 70% CPU usage on max. load.

We decided that this may be our problem since we experienced a similar problem 
at about 80% CPU load in the past.

So we upgraded the hardware. As expected, the CPU-load dropped to ~35% usage on 
max. load scenario.

But this did not solve the problem.

Same story for the harddisk system. The usage is not even near it's max 
capacity.



We also can't see any impact on the harddisk.

< p>We'r kind of stuck with our ideas, because we have no idea what could be a 
potential bottleneck to the system. 
Since the hardware doesn't show a limit, there have to be anything else - most 
likely firebird engine related that's limiting our system.

We would be very grateful if anyone can give us hints where we can search 
further.

Or someone has similar experiences to share with us.





Operating System: Windows Server 2003

Firebird: 2.1.5 Classic

Dedicated database server (VMWare)



CPU: 16 cores, each 2.4 GHz

RAM: 32 GB

About 14GB are used from OS and firebird processes under max load.


HDD: SAN Storage System



Average system IOPS under load read: 100

Average system IOPS under load write: 550

Backup Restore IOPS read: 1700

Backup Restore IOPS write: 250

SAN IPOS Limit (max): 3000



Firebird Config Settings, based on defaults

DefaultDbCachePages = 1024

LockMemSize = 134247728

LockHashSlots = 20011


Database

size: about 45 GB

450 to 550 concurrent connections

Daily average of 65 transactions / second (peak should be higher)



FB_LOCK_PRINT (without any params) while system was slowing down (~4 days 
uptime).

I have to note, Firebird was not able to print the complete output (stats was 
not cropped by me)



LOCK_HEADER BLOCK

Version: 16, Active owner:  0, Length: 134247728, Used: 82169316

Semmask: 0x0, Flags: 0x0001

Enqs: 4211018659, Converts: 10050437, Rejects: 9115488, Blocks: 105409192

Deadlock scans:   1049, Deadlocks:  0, Scan interval:  10

Acquires: 4723416170, A cquire blocks: 640857597, Spin count:   0

Mutex wait: 13.6%

Hash slots: 15077, Hash lengths (min/avg/max):3/  12/  25

Remove node:  0, Insert queue: 36, Insert prior: 74815332

Owners (456): forward: 131316, backward: 14899392

Free owners (9): forward: 39711576, backward: 49867232

Free locks (42409): forward: 65924212, backward: 23319052




With best Regards,



Patrick Friessnegg

Synesc GmbH

[firebird-support] as I can install firebird 3RC2 superclasic in linux?

2016-04-12 Thread 'Ismael L. Donis Garcia' sli...@citricos.co.cu [firebird-support] 
As I can install firebird 3 RC2 superclasic in linux?
I want to try it on devuan, I do not know as installing superclasic.
 
 Best Regards
 
 | ISMAEL |

Re: [firebird-support] String function extract last word from a string

2016-04-12 Thread Dimitry Sibiryakov s...@ibphoenix.com [firebird-support] 
12.04.2016 17:00, 'Checkmail' check_m...@satron.de [firebird-support] wrote:
> is it possible to extract the last complete word from a string until the last 
> blank? For
> example “I would like to eat a bacon” In this case I would like to have the 
> “bacon” as result.

   RIGHT(string, POSITION(' ' in REVERSE(string)))

-- 
   WBR, SD.






++

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on the main (top) menu.  Try FAQ and other links from the left-side menu there.

Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ 

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AW: [firebird-support] String function extract last word from a string

2016-04-12 Thread 'Checkmail' check_m...@satron.de [firebird-support] 
Thanks, I had a more complicated version tested now

  for select arbeitsgang from tarbg into :agbefore do
  begin
agafter = reverse(agbefore);
agafter = left(agafter, position(' ',agafter));
agafter = reverse(agafter);
suspend;
  end

-Ursprüngliche Nachricht-
Von: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] 
Gesendet: Dienstag, 12. April 2016 17:08
An: firebird-support@yahoogroups.com
Betreff: Re: [firebird-support] String function extract last word from a
string

12.04.2016 17:00, 'Checkmail' check_m...@satron.de [firebird-support] wrote:
> is it possible to extract the last complete word from a string until 
> the last blank? For example “I would like to eat a bacon” In this case I
would like to have the “bacon” as result.

   RIGHT(string, POSITION(' ' in REVERSE(string)))

-- 
   WBR, SD.






++

Visit http://www.firebirdsql.org and click the Documentation item on the
main (top) menu.  Try FAQ and other links from the left-side menu there.

Also search the knowledgebases at
http://www.ibphoenix.com/resources/documents/ 

++


Yahoo Groups Links

[firebird-support] String function extract last word from a string

2016-04-12 Thread 'Checkmail' check_m...@satron.de [firebird-support] 
Hello,

 

is it possible to extract the last complete word from a string until the
last blank? For example "I would like to eat a bacon" In this case I would
like to have the "bacon" as result.

 

Thank you.

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread 'Thomas Steinmaurer' t...@iblogmanager.com [firebird-support] 
Hi Patrick,

> Hi Thomas, nice to get a response from you. We already met in ~2010 in Linz at
> your office :)
> (ex. SEM GmbH, later Playmonitor GmbH)

I know. XING (Big Brother) is watching you. Nice to see that you are still 
running with Firebird. ;-)


> First, sorry for posting a mixed state of informations. The config settings i
> postet are the current settings.
> But the Lock-Table-Header was from last saturday (day of total system crash) -
> we changed Hash Slot Value since than, but it didn't work. New Table looks
> like:
> 
> 
> LOCK_HEADER BLOCK
> Version: 16, Active owner:  0, Length: 134247728, Used: 55790260
> Semmask: 0x0, Flags: 0x0001
> Enqs: 1806423519, Converts: 4553851, Rejects: 5134185, Blocks: 56585419
> Deadlock scans: 82, Deadlocks:  0, Scan interval:  10
> Acquires: 2058846891, Acquire blocks: 321584126, Spin count:   0
> Mutex wait: 15.6%
> Hash slots: 20011, Hash lengths (min/avg/max):0/   7/  18
> Remove node:  0, Insert queue:  0, Insert prior:  0
> Owners (297): forward: 385160, backward: 38086352
> Free owners (43): forward: 52978748, backward: 20505128
> Free locks (41802): forward: 180712, backward: 3620136
> Free requests (-1097572396): forward: 46948676, backward: 13681252
> Lock Ordering: Enabled
> 
> 
> The Min/Avg/Max hash lengths look better now, but as you mentioned the Mutex
> wait is worring us too.
> We have 2 direct questions about that.
> 
> 
> 1) What are the negative effects of increasing Hash-Slots (too high)?

It somehow defines the initial size of a hash table which is used for lock(ed) 
object lookup by a key (= hash value), ideally with constant O(1) run-time 
complexity. If the hash table is too small, due to a too small value for hash 
slots, it starts to degenerate into a linked/linear list per hash slot. Worst 
case resulting in O(n) complexity for lookups. The above 20011 setting shows an 
AVG hash length which looks fine.

As you might know, Classic having a dedicated process per connection model 
somehow needs a (global) mechanism to synchronize/protect shared data 
structures across these processes via IPC. This is what the lock manager and 
the lock table is used for.

> 2) As far as we know, we can't influence Mutex wait directly (it's just
> informational). But do you think that's the reason the underlying hardware is
> not utilized?

I don't think you are disk IO bound. Means, I'm not convinced that faster IO 
will help. Somehow backed by the high mutex wait. Under normal operations you 
see 100-500 IOPS with some room for further increase as shown in the 1700 IOPS 
backup use case. Don't know how random disk IO is in this two scenarios. Any 
chance to run some sort of disk IO benchmarks or do you already know your upper 
limits for your SAN IOPS wise?

> 
> 
> We do consider to upgrade to 2.5, but had our eyes on FB 3 over the last year,
> waiting for it to get ready.
> With 2.5.x we tested around a long time now, but never found a real reason to
> upgrade - since it's a reasonable amount of work for us. When you say it
> improves the lock contention, this sound pretty good. But again the question,
> do you think lock contention is limiting our system?

Dmitry, Vlad etc. will correct me (in case he is following the thread), but I 
recall that in 2.5, especially in SuperClassic being multi-threaded per worker 
process compared to Classic, now also allows specific(?) lock manager 
operations in parallel to regular request processing. In general I remember a 
mentioned improvement of ~25% in a TPC-C style workload with SuperClassic 
compared to Classic.

> 
> 
> First and foremost, we would really like to find the bottleneck. We just don't
> have the know-how to imagine something like "Fb 2.1 Engine is limiting us
> because of ..." and without that knowledge it's hard to take actions like
> upgrading to 2.5.
> 
> 
> We'll try to collect information about the garbage we create :) We do run
> "Sinatica Monitoring" on the server, which shows us "Awaiting Gargabe
> Collection" Transactions. Is that the information you'r looking for?

I'm not familiar with Sinatica. Perhaps the periodic MON$ queries (how frequent 
are they executed by Sinatica?) also produce some sort of overhead, cause each 
MON$ table query in context of a new physical transaction results in a stable 
view of current activity. Possibly not neglectable with > 400 connections.

The most easiest way to get insights on your record garbage is, e.g.:

* Run gstat -r
* Run a tool from IBSurgeon (can't recall the name, Alexey?)
* Run a tool from Upscene (FB TraceManager)

> 
> Maybe to avoid confusion, we don't have normal "Spikes" .. the system just
> starts to slow down and this state remains until the server-load is gone 
> (after
> midnight, when software is not used anymore).



--
With regards,
Thomas Steinmaurer
http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread 'Thomas Steinmaurer' t...@iblogmanager.com [firebird-support] 
> Thomas,
>>
>> I doubt, Firebird is IO-bound (limited by disk IO).
>>
> 
> Sorry, I don't understand your comment, can you please clarify what you 
> mean?

I think, disk IO isn't the limiting factor in that environment.



--
With regards,
Thomas Steinmaurer
http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread 'Thomas Steinmaurer' t...@iblogmanager.com [firebird-support] 
> Hi Patrick,
> 
> If you say that problem occurred recently, I would suggest you to check 
> SAN disks health.
> 
> However, these values
> 
>>Average system IOPS under load read: 100
> >Average system IOPS under load write: 550
> >Backup Restore IOPS read: 1700
> >Backup Restore IOPS write: 250
> 
> are really, really low.
> 1700 IOPS for the database with 4k page means 6.8Mb/sec (in case of 
> random reads).
> 
> I suggest to install a single SSD drive and check how it will work.
> SSD IOPS looks like
>   Random Read 4KB (QD=32) :   283.050 MB/s [ 69104.0 IOPS]
>   Random Write 4KB (QD=32) :   213.837 MB/s [ 52206.2 IOPS]
> 
> 
> From our optimization practice we found that if you need to optimize 
> only the single instance of the database, the most cost effective way is 
> to upgrade to SSD first, and only then fix other problems.

I doubt, Firebird is IO-bound (limited by disk IO).



--
With regards,
Thomas Steinmaurer
http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.


>> hi,
>>
>> recently we had some strange performance issues with our Firebird DB 
>> server.
>>
>> On high load, our server started to slow down. Select and update SQL 
>> query times did go up by more than 500% on average,
>>
>> but reaching unreasonable high execution times at worst case. (several 
>> minutes instead of < 1sec)
>>
>>
>> OIT/OAT/Next Transaction statistics was within 1000 the hole time
>>
>> We were not able to messure any hardware limiting factor. Indeed, this 
>> system was running with only 8 cores at about 70% CPU usage on max. load.
>>
>> We decided that this may be our problem since we experienced a similar 
>> problem at about 80% CPU load in the past.
>>
>> So we upgraded the hardware. As expected, the CPU-load dropped to ~35% 
>> usage on max. load scenario.
>>
>> But this did not solve the problem.
>>
>> Same story for the harddisk system. The usage is not even near it's 
>> max capacity.
>>
>>
>> We also can't see any impact on the harddisk.
>>
>> We'r kind of stuck with our ideas, because we have no idea what could 
>> be a potential bottleneck to the system.
>>
>> Since the hardware doesn't show a limit, there have to be anything 
>> else - most likely firebird engine related that's limiting our system.
>>
>> We would be very grateful if anyone can give us hints where we can 
>> search further.
>>
>> Or someone has similar experiences to share with us.
>>
>>
>>
>> Operating System: Windows Server 2003
>>
>> Firebird: 2.1.5 Classic
>>
>> Dedicated database server (VMWare)
>>
>>
>> CPU: 16 cores, each 2.4 GHz
>>
>> RAM: 32 GB
>>
>> About 14GB are used from OS and firebird processes under max load.
>>
>> HDD: SAN Storage System
>>
>>
>> Average system IOPS under load read: 100
>>
>> Average system IOPS under load write: 550
>>
>> Backup Restore IOPS read: 1700
>>
>> Backup Restore IOPS write: 250
>>
>> SAN IPOS Limit (max): 3000
>>
>>
>> Firebird Config Settings, based on defaults
>>
>> DefaultDbCachePages = 1024
>>
>> LockMemSize = 134247728
>>
>> LockHashSlots = 20011
>>
>> Database
>>
>> size: about 45 GB
>>
>> 450 to 550 concurrent connections
>>
>> Daily average of 65 transactions / second (peak should be higher)
>>
>>
>> FB_LOCK_PRINT (without any params) while system was slowing down (~4 
>> days uptime).
>>
>> I have to note, Firebird was not able to print the complete output 
>> (stats was not cropped by me)
>>
>>
>> LOCK_HEADER BLOCK
>>
>> Version: 16, Active owner:  0, Length: 134247728, Used: 82169316
>>
>> Semmask: 0x0, Flags: 0x0001
>>
>> Enqs: 4211018659, Converts: 10050437, Rejects: 9115488, Blocks: 105409192
>>
>> Deadlock scans:   1049, Deadlocks:  0, Scan interval:  10
>>
>> Acquires: 4723416170, Acquire blocks: 640857597, Spin count:   0
>>
>> Mutex wait: 13.6%
>>
>> Hash slots: 15077, Hash lengths (min/avg/max):3/  12/  25
>>
>> Remove node:  0, Insert queue: 36, Insert prior: 74815332
>>
>> Owners (456):forward: 131316, backward: 14899392
>>
>> Free owners (9):forward: 39711576, backward: 49867232
>>
>> Free locks (42409):forward: 65924212, backward: 23319052
>>
>>
>> With best Regards,
>>
>>
>> Patrick Friessnegg
>>
>> Synesc GmbH
>>
>> 
> 
>

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread Alexey Kovyazin a...@ib-aid.com [firebird-support] 

Hi Patrick,

If you say that problem occurred recently, I would suggest you to check 
SAN disks health.


However, these values


Average system IOPS under load read: 100

>Average system IOPS under load write: 550
>Backup Restore IOPS read: 1700
>Backup Restore IOPS write: 250

are really, really low.
1700 IOPS for the database with 4k page means 6.8Mb/sec (in case of 
random reads).


I suggest to install a single SSD drive and check how it will work.
SSD IOPS looks like
  Random Read 4KB (QD=32) :   283.050 MB/s [ 69104.0 IOPS]
  Random Write 4KB (QD=32) :   213.837 MB/s [ 52206.2 IOPS]


From our optimization practice we found that if you need to optimize 
only the single instance of the database, the most cost effective way is 
to upgrade to SSD first, and only then fix other problems.


Regards,
Alexey Kovyazin
IBSurgeon HQbird www.ib-aid.com




hi,

recently we had some strange performance issues with our Firebird DB 
server.


On high load, our server started to slow down. Select and update SQL 
query times did go up by more than 500% on average,


but reaching unreasonable high execution times at worst case. (several 
minutes instead of < 1sec)



OIT/OAT/Next Transaction statistics was within 1000 the hole time

We were not able to messure any hardware limiting factor. Indeed, this 
system was running with only 8 cores at about 70% CPU usage on max. load.


We decided that this may be our problem since we experienced a similar 
problem at about 80% CPU load in the past.


So we upgraded the hardware. As expected, the CPU-load dropped to ~35% 
usage on max. load scenario.


But this did not solve the problem.

Same story for the harddisk system. The usage is not even near it's 
max capacity.



We also can't see any impact on the harddisk.

We'r kind of stuck with our ideas, because we have no idea what could 
be a potential bottleneck to the system.


Since the hardware doesn't show a limit, there have to be anything 
else - most likely firebird engine related that's limiting our system.


We would be very grateful if anyone can give us hints where we can 
search further.


Or someone has similar experiences to share with us.



Operating System: Windows Server 2003

Firebird: 2.1.5 Classic

Dedicated database server (VMWare)


CPU: 16 cores, each 2.4 GHz

RAM: 32 GB

About 14GB are used from OS and firebird processes under max load.

HDD: SAN Storage System


Average system IOPS under load read: 100

Average system IOPS under load write: 550

Backup Restore IOPS read: 1700

Backup Restore IOPS write: 250

SAN IPOS Limit (max): 3000


Firebird Config Settings, based on defaults

DefaultDbCachePages = 1024

LockMemSize = 134247728

LockHashSlots = 20011

Database

size: about 45 GB

450 to 550 concurrent connections

Daily average of 65 transactions / second (peak should be higher)


FB_LOCK_PRINT (without any params) while system was slowing down (~4 
days uptime).


I have to note, Firebird was not able to print the complete output 
(stats was not cropped by me)



LOCK_HEADER BLOCK

Version: 16, Active owner:  0, Length: 134247728, Used: 82169316

Semmask: 0x0, Flags: 0x0001

Enqs: 4211018659, Converts: 10050437, Rejects: 9115488, Blocks: 105409192

Deadlock scans:   1049, Deadlocks:  0, Scan interval:  10

Acquires: 4723416170, Acquire blocks: 640857597, Spin count:   0

Mutex wait: 13.6%

Hash slots: 15077, Hash lengths (min/avg/max):3/  12/  25

Remove node:  0, Insert queue: 36, Insert prior: 74815332

Owners (456):forward: 131316, backward: 14899392

Free owners (9):forward: 39711576, backward: 49867232

Free locks (42409):forward: 65924212, backward: 23319052


With best Regards,


Patrick Friessnegg

Synesc GmbH

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread thetr...@yahoo.com [firebird-support] 
Hi Thomas, nice to get a response from you. We already met in ~2010 in Linz at 
your office :)
 (ex. SEM GmbH, later Playmonitor GmbH)
 

 First, sorry for posting a mixed state of informations. The config settings i 
postet are the current settings.
 But the Lock-Table-Header was from last saturday (day of total system crash) - 
we changed Hash Slot Value since than, but it didn't work. New Table looks like:
 

 LOCK_HEADER BLOCK
 Version: 16, Active owner:  0, Length: 134247728, Used: 55790260
 Semmask: 0x0, Flags: 0x0001
 Enqs: 1806423519, Converts: 4553851, Rejects: 5134185, Blocks: 56585419
 Deadlock scans: 82, Deadlocks:  0, Scan interval:  10
 Acquires: 2058846891, Acquire blocks: 321584126, Spin count:   0
 Mutex wait: 15.6%
 Hash slots: 20011, Hash lengths (min/avg/max):0/   7/  18
 Remove node:  0, Insert queue:  0, Insert prior:  0
 Owners (297): forward: 385160, backward: 38086352
 Free owners (43): forward: 52978748, backward: 20505128
 Free locks (41802): forward: 180712, backward: 3620136
 Free requests (-1097572396): forward: 46948676, backward: 13681252
 Lock Ordering: Enabled
 

 The Min/Avg/Max hash lengths look better now, but as you mentioned the Mutex 
wait is worring us too.
 We have 2 direct questions about that.
 

 1) What are the negative effects of increasing Hash-Slots (too high)?
 2) As far as we know, we can't influence Mutex wait directly (it's just 
informational). But do you think that's the reason the underlying hardware is 
not utilized?
 

 We do consider to upgrade to 2.5, but had our eyes on FB 3 over the last year, 
waiting for it to get ready.
 With 2.5.x we tested around a long time now, but never found a real reason to 
upgrade - since it's a reasonable amount of work for us. When you say it 
improves the lock contention, this sound pretty good. But again the question, 
do you think lock contention is limiting our system?
 

 First and foremost, we would really like to find the bottleneck. We just don't 
have the know-how to imagine something like "Fb 2.1 Engine is limiting us 
because of ..." and without that knowledge it's hard to take actions like 
upgrading to 2.5.
 

 We'll try to collect information about the garbage we create :) We do run 
"Sinatica Monitoring" on the server, which shows us "Awaiting Gargabe 
Collection" Transactions. Is that the information you'r looking for?
 

 Maybe to avoid confusion, we don't have normal "Spikes" .. the system just 
starts to slow down and this state remains until the server-load is gone (after 
midnight, when software is not used anymore).
 

 Best Regards,
 

 Patrick Friessnegg
 Synesc GmbH

Re: [firebird-support] [FB 2.1] Firebird engine seems to slow down on high load without utilizing hardware

2016-04-12 Thread Mark Rotteveel m...@lawinegevaar.nl [firebird-support] 
On 2016-04-11 13:55, thetr...@yahoo.com [firebird-support] wrote:
> hi,
>
> recently we had some strange performance issues with our Firebird DB
> server.
>
> We would be very grateful if anyone can give us hints where we can
> search further.
>
> Or someone has similar experiences to share with us.
>
> Operating System: Windows Server 2003
>
> Firebird: 2.1.5 Classic

At minimum update to Firebird 2.1.7, several bugs including security 
issues were fixed in 2.1.6 and 2.1.7.

Also consider to investigate upgrading to Firebird 2.5.x.


Mark