I am very new to solr cloud and now integration solr cloud with external zookeeper.
I want to run 4 solr cores on 4 different server and manage by zookeeper.
So, I run solr cores on 4 different ip servers with different ports, 8983,8984,8985,8986 and bind with zookeeper. and it okay.
But when I create collection with following commend in one of core
/opt/solr/bin/solr create -c articles -s 2 -rf 2
I got Error. because of remote server. but when I create 4 nodes in same ip with different port, it okay. Is there any command or any way to create 4 remote solr colres in solr cloud mode?
First of all check if cluster is configured correctly. Go to localhost:8983/solr/admin/collections?action=CLUSTERSTATUS and check if all 4 nodes are alive.
Then, have you tried to create the collection using the admin page?
Go to http://localhost:8983/solr and then go to Collections.
Click Add Collection button
name your collection, select a config name from the rop down list (you should have uploaded it in zookeeper first)
insert 2 as num shards, go to advanced and then select 2 as max shard per node
create the collection and see if it's ok selecting Cloud on menu.
Let me know if this works.
Related
I'm really new into learning MongoDB and I'm having a hard time trying to understand sharding.
So I have my PC who is the host and I have created two VMs using VirtualBox. In my PC (host) there is a DB with some data. So my issue is which of those 3 components should be the the Config Server, the Shard and the Query Router (mongo). Can somebody please help me explaining this ? (I have read the documentation and still haven't understand it completely).
A sharded cluster needs to run at least three processes, a "decent" sharded cluster runs at least 10 processes (1 mongos Router, 3 Config servers, 2 x 3 Shard servers). In production, they run on different machines, but it is no problem to run them all on the same machine.
I would suggest these steps for learning:
Deploy a Stand alone MongoDB
Deploy a Replica Set, see Deploy a Replica Set or Deploy Replica Set With Keyfile Authentication
Deploy a Sharded Cluster, see Deploy a Sharded Cluster or Deploy Sharded Cluster with Keyfile Authentication
In the beginning it is an overkill to use different machines. Use localhost for all.
You can run multiple mongod/mongos instances on one machine, just ensure they are using different ports (e.g. the default port 27017), different dbPath and preferable also different log files.
You may run your first trial without authentication. Once you got that working, use authentication with keyfile and as next step use authentication by x.509 certificates.
If you use Windows, then have a look at https://github.com/Wernfried/mongoDB-oneclick
I am going to create a load balancer in Azure. I have a VM that already running and going to take a backup of the existing VM and will create another VM using that backup. So two servers will have the same configuration and will use the same credentials.
In the already existing server, I have MongoDB configured, and if I create the same VM that will also have the same configuration as the old VM. Now what I want to know is can I use the same MongoDB which will be accessed by two servers that have the same configurations?
Will it create any mess or any give any error?
can I use like above mentioned?
Do I need to configure another MongoDB for the second server?
can anyone please clarify my questions? it would be great to have some clear explanation. thank you
MongoDB has build in support for horizontal scalability and high availability meaning that you dont need to create a 3th party load balancer , the mongos service part of mongoDB sharding cluster is the load balancer itself. Check the official documentation for mongoDB replication and sharding ...
On your questions:
Will it create any mess or any give any error?
If you just copy data to another VM it will be fine , as far as you dont write to one of the VMs you can loadbalance reads between this independent VMs , but this is strange approch when you have build in mongoDB replication mechanism and you can just add the second VM as a SECONDARY member from replicaSet.
can I use like above mentioned?
Sure , you can use also this approach but why you will need to do it?
Do I need to configure another MongoDB for the second server?
Depends on the use case , but in general you would prefer to create 3x members replicaSet or if your database is large and write performance is strong requirement you may need to distribute the database between multiple servers ( shards ) so you will need more then just 3x servers ...
I am new to orientdb. I use orientdb verson 2.1.11.
I config and deployed five nodes on the same machine in distribute mode. I use console to create a database, command is (port 2425 is the second node):
create database remote:192.168.12.37:2425/fuwu_test root 1234 plocal graph
Every node created the database "fuwu_test", but the cluster not create synchronous relationship.
I see the studio that every cluster has one cluster not five. I create one class Person, the class also not syncronized to other nodes.
Why it does't work, how to create a new datebase in running a cluster. Do I need to restart the whole nodes ?
thanks a lot
There is a known issue on this in v2.1 and v2.2 releases. The workaround is creating the database before to go in cluster. Anyway it will be resolved soon, sorry.
I've been investigating creating my own mongodb cluster in AWS. Aws mongodb template provides some good starting points. However, it doesn't cover auto scaling or when a node goes down. For example, if I have 1 primary and 2 secondary nodes. And the primary goes down and auto scaling kicks in. How would I add the newly launched mongodb instance to the replica set?
If you look at the template, it uses an init.sh script to check if the node being launched is a primary node and waits for all other nodes to exist and creates a replica set with thier ip addresses on the primary. When the Replica set is configured initailly, all the nodes already exist.
Not only that, but my node app uses mongoose. Part of the database connection allows you to specify multiple nodes. How would I keep track of what's currently up and running (I guess I could use DynamoDB but not sure).
What's the usual flow if an instance goes down? Do people generally manually re-configure clusters if this happens?
Any thoughts? Thanks.
This is a very good question and I went through this very painful journey myself recently. I am writing a fairly extensive answer here in the hope that some of these thoughts of running a MongoDB cluster via CloudFormation are useful to others.
I'm assuming that you're creating a MongoDB production cluster as follows: -
3 config servers (micros/smalls instances can work here)
At least 1 shard consisting of e.g. 2 (primary & secondary) shard instances (minimum or large) with large disks configured for data / log / journal disks.
arbiter machine for voting (micro probably OK).
i.e. https://docs.mongodb.org/manual/core/sharded-cluster-architectures-production/
Like yourself, I initially tried the AWS MongoDB CloudFormation template that you posted in the link (https://s3.amazonaws.com/quickstart-reference/mongodb/latest/templates/MongoDB-VPC.template) but to be honest it was far, far too complex i.e. it's 9,300 lines long and sets up multiple servers (i.e. replica shards, configs, arbitors, etc). Running the CloudFormation template took ages and it kept failing (e.g. after 15 mintues) which meant the servers all terminated again and I had to try again which was really frustrating / time consuming.
The solution I went for in the end (which I'm super happy with) was to create separate templates for each type of MongoDB server in the cluster e.g.
MongoDbConfigServer.template (template to create config servers - run this 3 times)
MongoDbShardedReplicaServer.template (template to create replica - run 2 times for each shard)
MongoDbArbiterServer.template (template to create arbiter - run once for each shard)
NOTE: templates available at https://github.com/adoreboard/aws-cloudformation-templates
The idea then is to bring up each server in the cluster individually i.e. 3 config servers, 2 sharded replica servers (for 1 shard) and an arbitor. You can then add custom parameters into each of the templates e.g. the parameters for the replica server could include: -
InstanceType e.g. t2.micro
ReplicaSetName e.g. s1r (shard 1 replica)
ReplicaSetNumber e.g. 2 (used with ReplicaSetName to create name e.g. name becomes s1r2)
VpcId e.g. vpc-e4ad2b25 (not a real VPC obviously!)
SubnetId e.g. subnet-2d39a157 (not a real subnet obviously!)
GroupId (name of existing MongoDB group Id)
Route53 (boolean to add a record to an internal DNS - best practices)
Route53HostedZone (if boolean is true then ID of internal DNS using Route53)
The really cool thing about CloudFormation is that these custom parameters can have (a) a useful description for people running it, (b) special types (e.g. when running creates a prefiltered combobox so mistakes are harder to make) and (c) default values. Here's an example: -
"Route53HostedZone": {
"Description": "Route 53 hosted zone for updating internal DNS (Only applicable if the parameter [ UpdateRoute53 ] = \"true\"",
"Type": "AWS::Route53::HostedZone::Id",
"Default": "YA3VWJWIX3FDC"
},
This makes running the CloudFormation template an absolute breeze as a lot of the time we can rely on the default values and only tweak a couple of things depending on the server instance we're creating (or replacing).
As well as parameters, each of the 3 templates mentioned earlier have a "Resources" section which creates the instance. We can do cool things via the "AWS::CloudFormation::Init" section also. e.g.
"Resources": {
"MongoDbConfigServer": {
"Type": "AWS::EC2::Instance",
"Metadata": {
"AWS::CloudFormation::Init": {
"configSets" : {
"Install" : [ "Metric-Uploading-Config", "Install-MongoDB", "Update-Route53" ]
},
The "configSets" in the previous example shows that creating a MongoDB server isn't simply a matter of creating an AWS instance and installing MongoDB on it but also we can (a) install CloudWatch disk / memory metrics (b) Update Route53 DNS etc. The idea is you want to automate things like DNS / Monitoring etc as much as possible.
IMO, creating a template, and therefore a stack for each server has the very nice advantage of being able to replace a server extremely quickly via the CloudFormation web console. Also, because we have a server-per-template it's easy to build the MongoDB cluster up bit by bit.
My final bit of advice on creating the templates would be to copy what works for you from other GitHub MongoDB CloudFormation templates e.g. I used the following to create the replica servers to use RAID10 (instead of the massively more expensive AWS provisioned IOPS disks).
https://github.com/CaptainCodeman/mongo-aws-vpc/blob/master/src/templates/mongo-master.template
In your question you mentioned auto-scaling - my preference would be to add a shard / replace a broken instance manually (auto-scaling makes sense with web containers e.g. Tomcat / Apache but a MongoDB cluster should really grow slowly over time). However, monitoring is very important, especially the disk sizes on the shard servers to alert you when disks are filling up (so you can either add a new shard to delete data). Monitoring can be achieved fairly easily using AWS CloudWatch metrics / alarms or using the MongoDB MMS service.
If a node goes down e.g one of the replicas in a shard, then you can simply kill the server, recreate it using your CloudFormation template and the disks will sync across automatically. This is my normal flow if an instance goes down and generally no re-configuration is necessary. I've wasted far too many hours in the past trying to fix servers - sometimes lucky / sometimes not. My backup strategy now is run a mongodump of the important collections of the database once a day via a crontab, zip up and upload to AWS S3. This means if the nuclear option happens (complete database corruption) we can recreate the entire database and mongorestore in an hour or 2.
However, if you create a new shard (because you're running out of space) configuration is necessary. For example, if you are adding a new Shard 3 you would create 2 replica nodes (e.g. primary with name => mongo-s3r1 / secondary with name => mongo-s3r2) and 1 arbitor (e.g. with name mongo-s3r-arb) then you'd connect via a MongoDB shell to a mongos (MongoDB router) and run this command: -
sh.addShard("s3r/mongo-s3r1.internal.mycompany.com:27017,mongo-s3r2.internal.mycompany.com:27017")
NOTE: - This commands assumes you are using private DNS via Route53 (best practice). You can simply use the private IPs of the 2 replicas in the addShard command but I have been very badly burned with this in the past (e.g. serveral months back all the AWS instances were restarted and new private IPs generated for all of them. Fixing the MongoDB cluster took me 2 days as I had to reconfigure everything manually - whereas changing the IPs in Route53 takes a few seconds ... ;-)
You could argue we should also add the addShard command to another CloudFormation template but IMO this adds unnecessary complexity because it has to know about a server which has a MongoDB router (mongos) and connect to that to run the addShard command. Therefore I simply run this after the instances in a new MongoDB shard have been created.
Anyways, that's my rather rambling thoughts on the matter. The main thing is that once you have the templates in place your life becomes much easier and defo worth the effort! Best of luck! :-)
Can we have this type of configuration?
Two server running the following things each-
1.Mongo Config Server.
2.Mongo Router.
3.Application.
Total 4 EC2 servers-
First Server-Running the web application & mongos.
Second Server-Running the web application & mongos.
Third Server-Running the First Shard with complete DB(Say for
example Demo).
Forth Server-Running The Second Shard with complete DB(Say for
example Demo).
Both the Mongos should point to one shard named Shard1?
Yes, You can have multiple mongos instances running against a single shard. Think of the mongos instances as clients for the sharded cluster which have to run as a daemon process in order to keep metadata and heartbeats up to date.
Edit: as for having a complete DB, this is only possible for a single DB. You can have one DB on shard1 and the other DB on shard2, for example. but you can never have a single complete DB on two shards. To achieve the goal of having db1 on shard1 and db2 on shard2, you simply make the respective shard the primary shard of the respective database and don't shard any collection. Please read the docs for the movePrimary command for details.
A bit OOT:
However, running a single config server is strongly advised against, and for a good reason. If the single config server goes down or gets corrupted, your cluster will be impossible to use - and recreating the sharded cluster will not an easy task to be done. And it's going to be a lengty process. So please, use three config servers.*