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Regarding Multi-Threading
Post 78496 by mbb on Wednesday 20th of July 2005 05:54:40 AM
07-20-2005
Sorry to hear that you cannot stop the querying process. This will limit your options.
Insert cursors are a way for your Esql/C process to buffer the inserts before they are committed to the database. I cannont comment on how that will affect the performance of your system overall, you would have to measure that. But they are the fastest way for you to insert records into a table via your program. After your load has been completed I recommend you still run update statistics.
As far a performance goes, you may want to pre-process the file and peform your validations before you attempt an insert run. Any exception records can be excluded from the insert run.
Since you have to run a large load in the exisiting environment and it is a one off, my best suggestion would be to validate and then load the file in much smaller chunks. Say 10,000 records at a time.
Therefore split the file into multiple files of 10,000 record chunks.
Write a validation program to validate a single file.
Write a load program to load a single file.
If you dont want to manage this all manually then,
write another(!) program to manage the loading of the small 10K files. You could create a table to store the name of the file, total number of rows, number of rows validated, rows loaded. This program would limit the number of concurrent loading processes (e.g. 10 at a time) and continue until all files have completed. You could add extra features such a reloading a failed file or allowing processing during a specific time frame.
Overall the loading process may take some time to complete, but I think you are now in a situation where you should be trying to spread and manage the workload.
Anyway, given all that you have told me that is how I would approach this task and I do appreciate that what I have described is not a trivial piece of work. (Loading high volumes of data to a live database never is
)
MBB
Insert cursors are a way for your Esql/C process to buffer the inserts before they are committed to the database. I cannont comment on how that will affect the performance of your system overall, you would have to measure that. But they are the fastest way for you to insert records into a table via your program. After your load has been completed I recommend you still run update statistics.
As far a performance goes, you may want to pre-process the file and peform your validations before you attempt an insert run. Any exception records can be excluded from the insert run.
Since you have to run a large load in the exisiting environment and it is a one off, my best suggestion would be to validate and then load the file in much smaller chunks. Say 10,000 records at a time.
Therefore split the file into multiple files of 10,000 record chunks.
Write a validation program to validate a single file.
Write a load program to load a single file.
If you dont want to manage this all manually then,
write another(!) program to manage the loading of the small 10K files. You could create a table to store the name of the file, total number of rows, number of rows validated, rows loaded. This program would limit the number of concurrent loading processes (e.g. 10 at a time) and continue until all files have completed. You could add extra features such a reloading a failed file or allowing processing during a specific time frame.
Overall the loading process may take some time to complete, but I think you are now in a situation where you should be trying to spread and manage the workload.
Anyway, given all that you have told me that is how I would approach this task and I do appreciate that what I have described is not a trivial piece of work. (Loading high volumes of data to a live database never is
)MBB
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LEARN ABOUT CENTOS
keepalived
KEEPALIVED(8) System Manager's Manual KEEPALIVED(8) NAME
keepalived - load-balancing and high-availability service SYNOPSIS
keepalived [-f|--use-file=FILE] [-P|--vrrp] [-C|--check] [-l|--log-console] [-D|--log-detail] [-S|--log-facility={0-7}] [-V|--dont-release-vrrp] [-I|--dont-release-ipvs] [-R|--dont-respawn] [-n|--dont-fork] [-d|--dump-conf] [-p|--pid=FILE] [-r|--vrrp_pid=FILE] [-c|--checkers_pid=FILE] [-v|--version] [-h|--help] DESCRIPTION
Keepalived provides simple and robust facilities for load-balancing and high-availability. The load-balancing framework relies on well-known and widely used Linux Virtual Server (IPVS) kernel module providing Layer4 load-balancing. Keepalived implements a set of checkers to dynamically and adaptively maintain and manage load-balanced server pool according their health. Keepalived also implements the VRRPv2 protocol to achieve high-availability with director failover. OPTIONS
-f, --use-file=FILE Use the specified configuration file. The default configuration file is "/etc/keepalived/keepalived.conf". -P, --vrrp Only run the VRRP subsystem. This is useful for configurations that do not use IPVS load balancer. -C, --check Only run the healthcheck subsystem. This is useful for configurations that use the IPVS load balancer with a single director with no failover. -l, --log-console Log messages to the local console. The default behavior is to log messages to syslog. -D, --log-detail Detailed log messages. -S, --log-facility=[0-7] Set syslog facility to LOG_LOCAL[0-7]. The default syslog facility is LOG_DAEMON. -V, --dont-release-vrrp Don't remove VRRP VIPs and VROUTEs on daemon stop. The default behavior is to remove all VIPs and VROUTEs when keepalived exits -I, --dont-release-ipvs Don't remove IPVS topology on daemon stop. The default behavior it to remove all entries from the IPVS virtual server table on when keepalived exits. -R, --dont-respawn Don't respawn child processes. The default behavior is to restart the VRRP and checker processes if either process exits. -n, --dont-fork Don't fork the daemon process. This option will cause keepalived to run in the foreground. -d, --dump-conf Dump the configuration data. -p, --pid=FILE Use specified pidfile for parent keepalived process. The default pidfile for keepalived is "/var/run/keepalived.pid". -r, --vrrp_pid=FILE Use specified pidfile for VRRP child process. The default pidfile for the VRRP child process is "/var/run/keepalived_vrrp.pid". -c, --checkers_pid=FILE Use specified pidfile for checkers child process. The default pidfile for the checker child process is "/var/run/keepalived_checkers.pid". -v, --version Display the version and exit. -h, --help Display this help message and exit. SEE ALSO
keepalived.conf(5), ipvsadm(8) AUTHOR
This man page was written by Ryan O'Hara <rohara@redhat.com> November 2012 KEEPALIVED(8)