dump datas from memcached to database

[Randy Wigginton]

I should have included disclaimers with the patch.  Its intended for  
debugging.  My cache has about 20K entries and it does not lock up  
the cache for any appreciable period.

Steve, care to show me how to lock down the keys on their way out?

On Feb 14, 2007, at 12:30 PM, Steven Grimm wrote:

> Be careful with that patch. No other client requests can be  
> serviced while that loop is running (which may be a long time if  
> your cache is large), but more critically, it doesn't lock down any  
> of the cache entries. While the results are getting streamed out to  
> the client, other clients can come in and change the cache, leading  
> to garbage output; for example, if a long key gets overwritten by a  
> short one before it's written, your list of "keys" will include the  
> short key's terminating null and the start of its data.
>
> Also, your client will probably get confused if you have a key  
> called "END" in your cache, but that's trivial to address.
>
> -Steve
>
>
> Randy Wigginton wrote:
>> ... unless you want to add a few lines of code to your version of  
>> memcached.
>>
>> Add this in, and send the command "keys <str>" and you will get a  
>> list of all keys containing that string,or just send "keys" and  
>> you'll get all.
>>
>>     if (strncmp(command, "keys", 4) == 0) {
>>         extern item** getHashtable();
>>         item **hashtable = getHashtable();
>>         unsigned long i;
>>         for (i=0; i<1<<16/*HASHPOWER*/; i++) {
>>             item *it = hashtable[i];
>>    int outOfMem = 0;
>>             while (it && !outOfMem) {
>>                 char *key = ITEM_key(it);
>>                 it = it->h_next;
>>     if (ntokens==3 && strstr(key, tokens[1].value)==NULL) {
>>      continue;
>>     }
>>     outOfMem = add_iov(c, key, strlen(key));
>>     outOfMem += add_iov(c, "\r\n", 2);
>>             }
>>         }
>>         add_iov(c, "END\r\n", 5);
>>
>>   conn_set_state(c, conn_write);
>>   c->write_and_go = conn_read;
>>  }
>>
>>
>> On Feb 14, 2007, at 11:33 AM, Ask Bjørn Hansen wrote:
>>
>>>
>>> On Feb 14, 2007, at 5:51 AM, Jm lists wrote:
>>>
>>>> Currently I want to use memcached as web's data cache.But I do need
>>>> the cached datas.So I want to dump datas to mysql periodicly.Can  
>>>> you
>>>> tell me how to dump all the datas stored in memcached?Thanks.
>>>
>>> You can't.
>>>
>>> http://www.socialtext.net/memcached/index.cgi? 
>>> faq#can_i_iterate_the_items_of_the_memcached_server
>>>
>>>
>>>  - ask
>>>
>>> -- 
>>> http://develooper.com/ - http://askask.com/
>>>
>>>
>>
>

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