Re: concurrency issues with one log file for multiple
log4j is thread safe and should handle the concurrency efficiently. I suggest you place tour OrderId in the log message using MDC. On Sat, Jun 20, 2009 at 12:12 PM, benedikt herudek benedikt.heru...@gmail.com wrote: Hi, we are intending to use log4J in a call center: we have around 100 simultaneous sessions working on one tool to create orders. W set up one logger per session (identified by basically the order id). All these loggers will write to one log file produced by log4J. Since we didnt use log4J before we want to be sure we are not creating concurrency issues and performance bottlenecks with having 100 session writing to one file. E.g. worst case scenario: 1st session loggs the file throughout its complete session and only releases it at the end, then in the meanwhile all other sessions queue up and wait. Rather, we suspect, log4J is automatically able to handle such a multiple sessions writing to one file situation and we dont have to bother with the details of that mechanism. Does anyone have experience, information, weblinks to documentation, tips or comments as to that problem ... ? ...:-) thx a lot !!! gruesse / regards / groetjes / adios Benedikt Herudek
Re: concurrency issues with one log file for multiple
I am using one logger per session and use the name of the logger to place in the log file, no nested diagnostic context. threadsafe in this context means: no blocking of whole file for one session, no building of queues I assume ... ? ... :-) regards Benedikt On Sun, Jun 21, 2009 at 8:36 AM, Yair Ogen yairo...@gmail.com wrote: log4j is thread safe and should handle the concurrency efficiently. I suggest you place tour OrderId in the log message using MDC. On Sat, Jun 20, 2009 at 12:12 PM, benedikt herudek benedikt.heru...@gmail.com wrote: Hi, we are intending to use log4J in a call center: we have around 100 simultaneous sessions working on one tool to create orders. W set up one logger per session (identified by basically the order id). All these loggers will write to one log file produced by log4J. Since we didnt use log4J before we want to be sure we are not creating concurrency issues and performance bottlenecks with having 100 session writing to one file. E.g. worst case scenario: 1st session loggs the file throughout its complete session and only releases it at the end, then in the meanwhile all other sessions queue up and wait. Rather, we suspect, log4J is automatically able to handle such a multiple sessions writing to one file situation and we dont have to bother with the details of that mechanism. Does anyone have experience, information, weblinks to documentation, tips or comments as to that problem ... ? ...:-) thx a lot !!! gruesse / regards / groetjes / adios Benedikt Herudek
Re: concurrency issues with one log file for multiple
AFAIK. On Sun, Jun 21, 2009 at 10:31 AM, benedikt herudek benedikt.heru...@gmail.com wrote: I am using one logger per session and use the name of the logger to place in the log file, no nested diagnostic context. threadsafe in this context means: no blocking of whole file for one session, no building of queues I assume ... ? ... :-) regards Benedikt On Sun, Jun 21, 2009 at 8:36 AM, Yair Ogen yairo...@gmail.com wrote: log4j is thread safe and should handle the concurrency efficiently. I suggest you place tour OrderId in the log message using MDC. On Sat, Jun 20, 2009 at 12:12 PM, benedikt herudek benedikt.heru...@gmail.com wrote: Hi, we are intending to use log4J in a call center: we have around 100 simultaneous sessions working on one tool to create orders. W set up one logger per session (identified by basically the order id). All these loggers will write to one log file produced by log4J. Since we didnt use log4J before we want to be sure we are not creating concurrency issues and performance bottlenecks with having 100 session writing to one file. E.g. worst case scenario: 1st session loggs the file throughout its complete session and only releases it at the end, then in the meanwhile all other sessions queue up and wait. Rather, we suspect, log4J is automatically able to handle such a multiple sessions writing to one file situation and we dont have to bother with the details of that mechanism. Does anyone have experience, information, weblinks to documentation, tips or comments as to that problem ... ? ...:-) thx a lot !!! gruesse / regards / groetjes / adios Benedikt Herudek
Changing log4j configuration runtime ...
Hello all,
I have successfully configured log4j in my standalone java application
using PropertyConfigurator.configure()
Here is the configuration file
log4j.rootLogger=DBUG, LogFile
log4j.logger.com.server.core=INFO
log4j.logger. com.server.core.SecurityManager =DEBUG
log4j.logger. com.server.core.SecurityPatternsCreator =DEBUG
log4j.appender.LogFile=org.apache.log4j.RollingFileAppender
log4j.appender.LogFile.File=c:/server.log
log4j.appender.LogFile.MaxFileSize=5MB
log4j.appender.LogFile.MaxBackupIndex=10
log4j.appender.LogFile.layout=org.apache.log4j.PatternLayout
log4j.appender.LogFile.layout.ConversionPattern=%d{
MM dd HH:mm:ss:SSS}# [%-5p]# [%t]# %c# %C{1}.%M# %m%n
In case of my application I have a security related library
(securitylib.jar) in which there we do some is a critical security
related processing. And I want to set logging level of INFO to all the
classes/loggers from this jar.
The log4j configuration is done before loading securitylib.jar using
above configuration file.
When securitylib.jar is loaded I tried to re-configure log4j using
following code.
(what I have done here is removed all the explicit loggers set in
configuration file, updated the configuration properties and configured
logger again)
But when I test the system I am still able to see the DEBUG logs for
classes/loggers com.server.core.SecurityManager and
com.server.core.SecurityPatternsCreator (which I had marked as DEBUG in
config files)
My questions are ...
1. Why after reconfiguring the loggers the new configuration is
not getting reflected ?
2. Is there any way to get the current log4j configuration and
change it at runtime ?
Thanks in advance for your help!
~PP
private void reinitLog4j()
{
try
{
String log4jFile = System.getProperty(log4j.file);
Properties properties = new Properties();
properties.load(new FileInputStream(log4jFile));
updateLoggingConfiguration(properties);
PropertyConfigurator.configure(properties);
}
catch (IOException ioEx)
{
throw new RuntimeException(failed to reconfigure
logger
+ ioEx.getMessage(), ioEx);
}
logger = Logger.getLogger(this.getClass());
logger.info(Log4j RE initialised to use INFO logs
everywhere !);
logger.debug(THIS SHOULD NEVER COME IN LOGS);
}
private void updateLoggingConfiguration(Properties properties)
{
for (Iterator iterator =
properties.entrySet().iterator(); iterator
.hasNext();)
{
Entry entry = (Entry) iterator.next();
String key = (String) entry.getKey();
if (key.equalsIgnoreCase(log4j.rootLogger))
{
entry.setValue(getRootLoggerConfiguration((String) entry
.getValue()));
}
else if (key.startsWith(log4j.logger))
{
iterator.remove();
}
}
}
private String getRootLoggerConfiguration(String currentConfig)
{
String[] tokens = IOUtil.tokenizeString(currentConfig,
,);
StringBuilder builder = new StringBuilder();
for (int i = 0; i tokens.length; i++)
{
if (i == 0)
{
builder.append(INFO);
continue;
}
builder.append(, + tokens[i]);
}
return builder.toString();
}
Re: Changing log4j configuration runtime ...
Why not use a regular property file?
Then when you to update the file you can load the changes automatically
using the PropertyConfigurator.configureAndWatch mechanism.
On Sun, Jun 21, 2009 at 11:41 AM, Preetam Palwe preet...@aftek.com wrote:
Hello all,
I have successfully configured log4j in my standalone java application
using PropertyConfigurator.configure()
Here is the configuration file
log4j.rootLogger=DBUG, LogFile
log4j.logger.com.server.core=INFO
log4j.logger. com.server.core.SecurityManager =DEBUG
log4j.logger. com.server.core.SecurityPatternsCreator =DEBUG
log4j.appender.LogFile=org.apache.log4j.RollingFileAppender
log4j.appender.LogFile.File=c:/server.log
log4j.appender.LogFile.MaxFileSize=5MB
log4j.appender.LogFile.MaxBackupIndex=10
log4j.appender.LogFile.layout=org.apache.log4j.PatternLayout
log4j.appender.LogFile.layout.ConversionPattern=%d{
MM dd HH:mm:ss:SSS}# [%-5p]# [%t]# %c# %C{1}.%M# %m%n
In case of my application I have a security related library
(securitylib.jar) in which there we do some is a critical security
related processing. And I want to set logging level of INFO to all the
classes/loggers from this jar.
The log4j configuration is done before loading securitylib.jar using
above configuration file.
When securitylib.jar is loaded I tried to re-configure log4j using
following code.
(what I have done here is removed all the explicit loggers set in
configuration file, updated the configuration properties and configured
logger again)
But when I test the system I am still able to see the DEBUG logs for
classes/loggers com.server.core.SecurityManager and
com.server.core.SecurityPatternsCreator (which I had marked as DEBUG in
config files)
My questions are ...
1. Why after reconfiguring the loggers the new configuration is
not getting reflected ?
2. Is there any way to get the current log4j configuration and
change it at runtime ?
Thanks in advance for your help!
~PP
private void reinitLog4j()
{
try
{
String log4jFile = System.getProperty(log4j.file);
Properties properties = new Properties();
properties.load(new FileInputStream(log4jFile));
updateLoggingConfiguration(properties);
PropertyConfigurator.configure(properties);
}
catch (IOException ioEx)
{
throw new RuntimeException(failed to reconfigure
logger
+ ioEx.getMessage(), ioEx);
}
logger = Logger.getLogger(this.getClass());
logger.info(Log4j RE initialised to use INFO logs
everywhere !);
logger.debug(THIS SHOULD NEVER COME IN LOGS);
}
private void updateLoggingConfiguration(Properties properties)
{
for (Iterator iterator =
properties.entrySet().iterator(); iterator
.hasNext();)
{
Entry entry = (Entry) iterator.next();
String key = (String) entry.getKey();
if (key.equalsIgnoreCase(log4j.rootLogger))
{
entry.setValue(getRootLoggerConfiguration((String) entry
.getValue()));
}
else if (key.startsWith(log4j.logger))
{
iterator.remove();
}
}
}
private String getRootLoggerConfiguration(String currentConfig)
{
String[] tokens = IOUtil.tokenizeString(currentConfig,
,);
StringBuilder builder = new StringBuilder();
for (int i = 0; i tokens.length; i++)
{
if (i == 0)
{
builder.append(INFO);
continue;
}
builder.append(, + tokens[i]);
}
return builder.toString();
}
