Trying to push Kafka stream data into the Redis, command does not raise any error, and nothing gets to write into Redis.
Here is the command:
./bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test --from-beginning | redis-cli -x rpush stepanova
It does not write anything to the "stepanova" key.
Is there something missing?
Related
I am trying to use redis-cli --pipe to bulk upload some commands to my AWS Elasticache for redis cluster. The commands come from parsing a file via a custom awk command, which helps generate some HSET commands. The awk command is in a custom shell script. When my Elasticache for redis server had cluster-mode disabled, doing something like the following worked like a charm:
sh script_containing_awk.sh $FILE_TO_PARSE | redis-cli -h <Primary_endpoint> -p <port> --tls --cacert <path/to/cert> --pipe
Due to an internal project requirement, the Elasticache for Redis server has been re-created with cluster-mode enabled, and hence I am adding the -c flag to the above command to specify as such.
I see the following results when trying to work with my Elasticache for Redis server with cluster-mode enabled:
I can connect to the cluster via the configuration endpoint no problem!
Single command uploads work (i.e: redis-cli -h <config_endpoint> -p <port> -c --tls --cacert <path/to/certs> SET key value)
It would be extremely convenient to just pipe output from my script to the cli:
sh script_containing_awk.sh $FILE_TO_PARSE | redis-cli -h <config_endpoint> -p <port> -c --tls --cacert <path/to/cert> --pipe
but adding the --pipe flag results in "MOVED" errors.
I have tried modifying the script to include {} (ex: HSET {user1}:hash field1 val1 field2 val2 ... brackets to try to force keys to the same CLUSTER SLOTS, but I still get the "MOVED" errors and I am attempting to bulk upload millions of keys so I don't think they would all fit in the same slot anyway.
Does anyone have experience getting --pipe to work with cluster-mode enabled Redis/Elasticache?
Thanks!
I am sure you understand that the core difference between Cluster Mode Disabled and Cluster Mode Enabled is that there is a split in your total Key slots.
Just to put in context;
CMD - Let's say we have 4 node cluster with 1 Primary and 3 Replicas.
if we have 100 key slots -
All the 100 key slots will be there in all the nodes. 3 of them will serve Read only commands and 1 of the node will serve all the commands.
CME - Let's say we have 4 nodes split in 2 shards - 1 replica and 1 primary each.
We can look at them as logical sub-clusters ie. they will have different sets of key-slots. Ideally a 50-50 split.
Now, the MOVED message is not necessarily an error.
When you connect to the configuration endpoint, by default you are being connected with one of the primary nodes (chosen at random, at first).
when you make a command, the client sends that command and the primary node decides if it has the correct hash-slot to serve that command.
As explained here, if the node does not have the hash-slot that your client is looking for, it will redirect you with a MOVED message.
So, I would assume MOVED messages are somewhat expected with CME clusters.
When a Redis instance is setup and running, the dataset size (in bytes) can be retrieved from output of the below command by looking at used_memory_dataset field.
./redis-cli -h <ip address> -p <port> info
However, when I have multiple instances running in the cluster mode, how do I retrieve the dataset size across the cluster? Can redis-cli tool still be used for such cluster-based commands?
As of Redis v5 the cli includes cluster-smarts. You can use the following form to call a command, e.g. INFO, on all nodes:
redis-cli --cluster call ip:port command
To calculate the dataset's total size, you'd have to add up the different replies.
I have a health check I'm trying to use that executes the redis-cli command from the redis servers to the redis-sentinels remotely.
redis-cli -h 10.10.10.10 -p 26379 SENTINEL MASTER testing
There is a logic that sorts out whether there is a quorum and it all works fine unless a sentinel's network interface is unavailable. The redis-cli command hangs indefinitely in this case and the health check fails even though there are two healthy sentinels with a quorum.
I can't seem to find a way to set a timeout for the redis-cli on the client side to prevent it from hanging. Is there a way with redis-cli to do this or will I have to go outside the command to ensure it doesn't hang indefinitely?
I decided to use the timeout command to wrap the redis-cli command. It seems to work very well for my purposes!
timeout 3 redis-cli -h 10.10.10.10 -p 26379 SENTINEL MASTER testing
I am trying to test my cache was implemented with redis clustering (cluster by server not client).
I have to flush redis every time I run a unit test.
when I try to run flushdb command I got this error:
Cannot use 'FLUSHDB' with redis-cluster.
it seems that I can run flushdb command in cluster mode only when I set the slot but I do not know how to do it. (I have overridden redis wrapper of laravel so laravel is not the case If you learn me how to use predis I can adopt it with laravel)
For deleting by pattern:
redis-cli --raw keys "$PATTERN" | xargs redis-cli del
for example:
redis-cli KEYS "prefix:*" | xargs redis-cli DEL
For deleting all keys from one db:
redis-cli flushdb
For deleting all keys from all dbs:
redis-cli flushall
For cluster mode you need to use this bash script:
https://gist.github.com/yaud/85e0382d26c189bdf84f0297cd54f479
to remove all nodes from master nodes (slave nodes will be synced)
I'm trying to import one million lines of redis commands, using the --pipe feature.
redis_version:2.8.1
cat file.txt | redis-cli --pipe
This results in the following error:
Error reading from the server: Connection reset by peer
Does anyone know what I'm doing wrong?
file.txt contains, for example,
lpush name joe
lpush name bob
edit: I now see there's probably a special format(?) for using pipe mode - http://redis.io/topics/protocol
The first point is that the parameters have to be double-quoted. The documentation is somewhat misleading on this point.
So a working syntax is :
lpush "name" "joe"
lpush "name" "bob"
The second point is that each line has to end by an \r\n and not just by \n. To fix that point, you just have to convert your file with the command unix2dos
like : unix2dos file.txt
Then you can import your file using cat file.txt | src/redis-cli --pipe
This worked for me.
To use the pipe mode (a.k.a bulk loading, or mass insertion) you must indeed provide your commands directly in Redis protocol format.
The corresponding Redis protocol for LPUSH name joe is:
*3
$5
LPUSH
$4
name
$3
joe
Or as a quoted string: "*3\r\n$5\r\nLPUSH\r\n$4\r\nname\r\n$3\r\njoe\r\n".
This is what your input file must contain.
Redis documentation includes a Ruby sample to help you generate the protocol: see gen_redis_proto.
A Python sample is available e.g. in the redis-tools package.
There are existing tools that convert client commands directly to redis wire protocol messages. Example:
redis-mass my-client-script.txt | redis-cli --pipe option
https://golanglibs.com/dig_in/redis-mass
https://github.com/almeida/redis-mass
There are two kinds of possibilities.
First check point is exceed of maxclients limits.
You can check using 'info clients' and 'config get maxclients' redis command.
In my desktop result is below.
127.0.0.1:6379> info clients
# Clients
connected_clients:2
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0
127.0.0.1:6379> config get maxclients
1) "maxclients"
2) "2"
and then i tried to use pipe command, below is result.
[localhost redis-2.8.1]$ cat test.txt | ./src/redis-cli --pipe
All data transferred. Waiting for the last reply...
Error reading from the server: Connection reset by peer
If that result is same. you have to change redis.conf file.
Seconds check point is ulimit option.
ulimit option change needs a root privilige. check below link.
How do I change the number of open files limit in Linux?
This error happens because the timeout set in Redis is Default, 0. You need to configure this timeout value by redis-cli using the command below:
To connect in redis server:
redis-cli -h -p -a
To view timeout value configured:
this command-line: config get timemout, Works to see what is the timeout value was configured in Redis server.
To Set new value for redis timeout:
this command-line: config set timeout 120, Set the timeout to 2 minutes. So, you need to set the redis timeout so long your execution need.
I hope this answers help you. Cyu!!!
You can use the following command to import your file's data to redis
cat file.txt | xargs -L1 redis-cli