Soft-Error on connection-issues

[senfomat]

Is there a possibility to get a more soft error from RedisDB on connection-issues? The current situation simply exits the running script via croak. Which in my case is problematic, because the script has to return data even without a working redis-connection.

[trinitum]

You can wrap call to redis into eval, or use Try::Tiny. If it is not suitable for you, can you provide an example of the desired behaviour?

[senfomat]

Its a little based on the error-handling of the DBI-Module.

The "err"- and "errstr"-Attributes should be cleared on every request, so it gives only errors on the last action.

Example:

use RedisDB;

my $redis = RedisDB->new(
                        path      => '/path/to/redis.sock',
                        softerror => 1,
                );

LINE:
while(my $key = <>)
{
   chomp($key);
   my $value = $redis->get("whatever::$key");
   if (defined $redis->err)
   {
      # Log an Error or a warning, warn() only as example
      warn($redis->errstr);

      # give something like a temporary error to the application
      # ...

      next LINE;
   }

   # do something with $value
   # ...
}

In the current implementation I have to wrap every call to redis in Try-Tiny or eval, becaus on every error the script exits right away. The wrapping is more complicated when doing multipe requests, I think. So an in-module-solution would be very nice.

Thank you.

[trinitum]

Ok, but then after every call to redis you will have to check the error, which is not that much better.

Give me some time, I need to think about it and look how I can implement it.

[trinitum]

Sorry for the long silence. I added raise_error parameter which is true by default. If you set it to false, get_reply, execute, and synchronous command wrappers will return RedisDB::Error object instead of dying when server returns an error. E.g.:

$redis = RedisDB->new(raise_error => 0);
...;
$res = $redis->get('key');
if (ref $res eq 'RedisDB::Error') {
    # handle error
    ...;
}

This is in line with how callbacks handle errors. I also think about improving connect/reconnect errors handling, perhaps I will add some callbacks for this. Cases when data was lost as a result of disconnect or invalid data came from the server will still throw exceptions and I don't have plans to do anything about it. If you really want to ignore such errors I would recommend you to subclass RedisDB and wrap execute method into eval block using Class::Method::Modifiers.

[trinitum]

I uploaded RedisDB 2.10 to CPAN, it comes with raise_error option. I also added on_connect_error callback which may help in case of connection problems.