[Sheepdog] [PATCH v2] logger: rotate log by size, default is 500MB

[Liu Yuan]

On 04/09/2012 05:57 PM, zituan at taobao.com wrote:

> From: Andy Chen <sanjie.cyg at taobao.com>
> 
> a simple patch to split log:  when log size exceed 500MB, a new
> sheep.log file will be created, and old log will be renamed with
> specified suffix(actually, it's the time when split happened).
> 
> the main purpose of this patch is to prevent log became too big,
> which is hard to open and read.
> 
> Signed-off-by: Andy Chen <sanjie.cyg at taobao.com>
> Signed-off-by: Yibin Shen <zituan at taobao.com>
> ---
>  lib/logger.c |   47 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 47 insertions(+), 0 deletions(-)
> 
> diff --git a/lib/logger.c b/lib/logger.c
> index d5eb453..56da6d7 100644
> --- a/lib/logger.c
> +++ b/lib/logger.c
> @@ -28,6 +28,7 @@
>  #include <sys/types.h>
>  #include <sys/wait.h>
>  #include <sys/prctl.h>
> +#include <pthread.h>
>  
>  #include "logger.h"
>  #include "util.h"
> @@ -47,10 +48,15 @@ static void dolog(int prio, const char *func, int line, const char *fmt,
>  
>  static struct logarea *la;
>  static char *log_name;
> +static char *log_nowname;
>  static int log_level = SDOG_INFO;
>  static pid_t pid;
>  static key_t semkey;
>  
> +static int64_t max_logsize = 500 * 1024 * 1024;  /*500MB*/
> +
> +pthread_mutex_t logsize_lock = PTHREAD_MUTEX_INITIALIZER;
> +
>  static int logarea_init(int size)
>  {
>  	int shmid;
> @@ -317,6 +323,29 @@ static void dolog(int prio, const char *func, int line, const char *fmt, va_list
>  	}
>  }
>  
> +static void rotate_log(void)
> +{
> +	int new_fd;
> +
> +	if (access(log_nowname, R_OK) == 0) {
> +		char old_logfile[256];
> +		time_t t;
> +		struct tm tm;
> +		time(&t);
> +		localtime_r((const time_t *)&t, &tm);
> +		sprintf(old_logfile, "%s.%04d-%02d-%02d-%02d-%02d",
> +				log_nowname, tm.tm_year + 1900, tm.tm_mon + 1,
> +				tm.tm_mday, tm.tm_hour, tm.tm_min);
> +		rename(log_nowname, old_logfile);
> +	}
> +	new_fd = open(log_nowname, O_RDWR | O_CREAT | O_APPEND, 0644);
> +	if (new_fd < 0)
> +		syslog(LOG_ERR, "fail to create new log file\n");
> +
> +	dup2(new_fd, la->fd);
> +	la->fd = new_fd;
> +}
> +
>  void log_write(int prio, const char *func, int line, const char *fmt, ...)
>  {
>  	va_list ap;
> @@ -369,10 +398,14 @@ static void log_sigexit(int signo)
>  
>  int log_init(char *program_name, int size, int is_daemon, int level, char *outfile)
>  {
> +	off_t offset;
> +	size_t log_size;
> +
>  	log_level = level;
>  
>  	logdbg(stderr, "entering log_init\n");
>  	log_name = program_name;
> +	log_nowname = outfile;
>  
>  	semkey = random();
>  
> @@ -436,6 +469,20 @@ int log_init(char *program_name, int size, int is_daemon, int level, char *outfi
>  
>  		while (la->active) {
>  			log_flush();
> +
> +			if (max_logsize) {
> +				pthread_mutex_lock(&logsize_lock);
> +				offset = lseek(la->fd, 0, SEEK_END);
> +				if (offset < 0) {
> +					syslog(LOG_ERR, "sheep log error\n");
> +				} else {
> +					log_size = (size_t)offset;
> +					if (log_size >= max_logsize)
> +						rotate_log();
> +				}
> +				pthread_mutex_unlock(&logsize_lock);
> +			}
> +
>  			sleep(1);
>  		}
>  


Applied

Thanks,
Yuan