I want to list all the keys stored in the memcached server.
I googled for the same, I got some python/php scripts that can list the same. I tested it but all went failed and none gave me full keys. I can see thousands of keys using telnet command
stats items
I used perl script that uses telnet to list keys, but that got failed too. I mean that script is listing keys but not all of them.
Do I need to reconfigure telnet ? Is there any other way ?
memcache does not provide an api to exhaustively list all keys. "stats items" is as good as it gets to list the first 1M of keys. More info here: http://www.darkcoding.net/software/memcached-list-all-keys/
Not sure if that helps you but redis (which could be considered a superset of memcache) provides a more comprehensive API for key listing and searching. You might want to give it a try.
It you use python-memcached, and would like to export all the items in memcache server, I summerized two methods to the problem in this question: Export all keys and values from memcached with python-memcache
Related
I have my instance running and am able to connect remotely however I'm stuck on where to set this parameter to false since it states that the default is set to true:
failIndexKeyTooLong
Setting the 'failIndexKeyTooLong' is a three-step process:
You need to go to the command console in the Tools menu item for the admin database of your database instance. This command will only work on the admin database, pictured here:
Once there, pick any command from the list and it will give you a short JSON text for that command.
Erase the command they provide (I chose 'ping') and enter the following JSON:
{
"setParameter" : 1,
"failIndexKeyTooLong" : false
}
Here is an example to help:
Note if you are using a free plan at MongoLab: This will NOT work if you have a free plan; it only works with paid plans. If you have the free plan, you will not even see the admin database. HOWEVER, I contacted MongoLab and here is what they suggest:
Hello,
First of all, welcome to MongoLab. We'd be happy to help.
The failIndexKeyTooLong=false option is only necessary when your data
include indexed values that exceed the maximum key value length of
1024 bytes. This only occurs when Parse auto-indexes certain
collections, which can actually lead to incorrect query results. Parse
has updated their migration guide to include a bit more information
about this, here:
https://parse.com/docs/server/guide#database-why-do-i-need-to-set-failindexkeytoolong-false-
Chances are high that your migration will succeed without this
parameter being set. Can you please give that a try? If for any reason
it does fail, please let us know and we can help you on potential next
steps.
Our Dedicated and Shared Cluster plans
(https://mongolab.com/plans/pricing/) do provide the ability to toggle
this option, but because our free Sandbox plans are running on shared
server processes, with other Sandbox users, this parameter is not
configurable.
When launching your mongodb server, you can set this parameter to false :
mongod --setParameter failIndexKeyTooLong=false
I have wrote an article that help you to Setting up Parse-Server and all its dependencies on your own server:
https://medium.com/#jcminarro/run-parse-server-on-your-own-server-using-digitalocean-b2a7d66e1205
I know that it is possible to display the value of a key that is part of a Map that was stored in hazelcast using REST.
Using curl this would be done this way:
curl -v -X GET http://127.0.0.1:5701/hazelcast/rest/maps/myMap/nameOfKeyInMap
But what if I don't know which keys were used ? Following REST principles I skipped the nameOfKeyInMap part of the URL and expected Hazelcast to return a list of keys. But it didn't.
Do you know a way to get at least a part of the keys used ? I use Hazelcast 3.4 and checked the manual but didn't find a solution
I want to use REST because I need to have people check the maps that don't have much more than a browser on their computers.
I'm using xmemcached client.
Is there a mechanism or best way to control from client side the distribution of the keys
per server, i.e. I want to make sure all the keys following a certain custom pattern to be stored in server1, while the others in server 2.
A simple example: all my keys starting with 'a' should go into server 1 while the others into server 2.
I found a question and that is : to implement a key-value server
User should be able to connect to server and be able to run command SET a = b.
On running command GET a, it should print b.
First of all, I didn't really understand what the question is all about.
In its simplest form, a Key-Value server is nothing more but a server that holds keys in a dictionary structure and associates a value with said key.
If it helps, you can think of a key as a variable name in a programming language or as an environment variable in the bash shell.
A client to the Key-Value server would either tell the server what value the key has, or request the current value of the key from the server.
As Ramon mentioned in his comment, memcached.org is such example of a Key-Value server.
Of course, the server can be much more complex that what I described above. Keys could be more than just values (for instance, objects) and the server/client could have a lot more functionality than the basic set/get.
Note that the term Key-Value server is very broad and doesn't mean anything concrete by itself. NoSQL systems make use of key-value stores, for example, so you could technically call any NoSQL database system a Key-Value server.
I just installed memcache in my machine.Actually,i have to create regions in there.
For eg there should be 3 regions created ,each storing a set of data.Am not sure how can i do that in memcache.Can anyone please help/give eg as it is "urgent".
Thanks in advance
Memcached itself is just a service that runs on your server. It can be connected to and commands sent to it over a text based protocol. Once the service is running, you can use a tool such as telnet or netcat to interact with it.
As for accessing from Java, you'll probably want a library to do most of the work for you. There were a few listed on this question: Java Memcached Client
Now as for your regions: memchached is basically a key/value table. To set a region you'd do something like memcached.set("key", yourData) and to get it back you'd do something like yourData = memcached.get("key")
Note that these functions will vary depending which library you are using.