After Download AgensGraph from "https://github.com/bitnine-oss/agensgraph".
When configure and install done, I try to connect AgensGraph.
It failed like this :
agens: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
How to start AgensGraph server on Mac OS X?
You must initialize & create database before connecting to AgensGraph.
First, Set environment variable.
$ export AGDATA=~/Download/pgsql/data
Next, Initialize database.
$ initdb
The files belonging to this database system will be owned by user "assam".
This user must also own the server process.
The database cluster will be initialized with locale "ko_KR.UTF-8".
The default database encoding has accordingly been set to "UTF8".
initdb: could not find suitable text search configuration for locale "ko_KR.UTF-8"
The default text search configuration will be set to "simple".
Data page checksums are disabled.
creating directory /Users/assam/Download/pgsql/data ... ok
creating subdirectories ... ok
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting dynamic shared memory implementation ... posix
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok
WARNING: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the option -A, or
--auth-local and --auth-host, the next time you run initdb.
Success. You can now start the database server using:
ag_ctl -D /Users/assam/Download/pgsql/data -l logfile start
Next, Startup database.
$ ag_ctl start
server starting
Next, Create database.
$ createdb
Finally, Connect to AgensGraph.
$ agens
agens (AgensGraph 1.3.1, based on PostgreSQL 9.6.2)
Type "help" for help.
assam=#
For shutdown Agensgraph.
$ ag_ctl stop
waiting for server to shut down.... done
server stopped
Related
I recently had to add clickhouse to our technology stack but unfortunately I didn't find any good, simple and fast tutorials for my needs and after some trial and error I could manage to do it by myself. To help others I decided to share my experience.
So how to deploy and configure a remote ClickHouse DB instance with docker?
ClickHouse setup
This is a setup guide for deploying ClickHouse with docker on remote servers.
Installation
You have to have docker preinstalled on your remote system.
Server
Run the following command:
$ docker run -d --name some-clickhouse-server -p 8123:8123 --ulimit nofile=262144:262144 --volume=$HOME/some_clickhouse_database:/var/lib/clickhouse yandex/clickhouse-server
ClickHouse server uses port 8123 as the default port but you can uses any other open port but remember to expose the port to the external network. The server comes with a default users with no password.
Client
Run the following command in the server to connect to the clickhouse server with the default user.
$ docker run -it --rm --link some-clickhouse-server:clickhouse-server yandex/clickhouse-client --host clickhouse-server
Configuration
Open the clickhouse server docker container
$ docker exec -it some-clickhouse-server bash
1. Enable SQL-driven access control and account management for the default user.
In the clickhouse server docker container:
$ cd etc/clickhouse-server
Comment out the following line in user.xml file to enable access control:
<access_management>1</access_management>
Note that this operation is unsafe and after finishing you work, you should change the access control to :
<access_management>0</access_management>
2. Listening to other networks:
In the etc/clickhouse-server/config.xml comment out <listen_host>::</listen_host> to allow remote connections.
You should see the port is open in the systems network:
root#myvm:~# lsof -i :8123
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
docker-pr 1141768 root 4u IPv6 53989091 0t0 TCP *:8123 (LISTEN)
Creating a DB with users
In this part we create a simple database and a users. Then we Grant privileges of the database to that user.
There are two types of synchronization and they can complement each other:
1. Creating an users
CREATE USER IF NOT EXISTS user1 IDENTIFIED WITH PLAINTEXT_PASSWORD BY 'pass1'
You can check the users with the SHOW USERS command.
2. Creating a database
CREATE DATABASE IF NOT EXISTS db1
You can check the databases with the SHOW DATABASES command.
3. Grant database privileges to the user
You can grant limited privileges or all privileges to a users.
GRANT ALL PRIVILEGES ON db1.* TO user1
4. Connect with the new users to the database
Now we can connect to the server with the created account.
$ docker run -it --rm --link some-clickhouse-server:clickhouse-server yandex/clickhouse-client --host clickhouse-server -u user1 --password pass1
Make sure the users has all the permissions and has access to the databases:
:) SHOW GRANTS
:) SHOW DATABASES
Creating a Sample Table
Clickhouse supports SQL .
To create a table:
:) USE db1
:) CREATE TABLE names (
id UInt64,
name String,
created DateTime
) ENGINE = MergeTree()
PRIMARY KEY id
ORDER BY id;
:) SHOW TABLES
There you have it. You can connect to the databases from other networks with the clickhouse-client and your user/password.
Please clone this project and follow the instructions as per the README.md file. After running the docker compose you will have 2 shards and 2 replica setup of clickhouse.
https://github.com/vinitk95/clickhouse-cluster.git
I need to import a old db into a new postgre server.
Is there a way to migrate an old database to a new server without using pg_dump?
I don't have the sql file, or the old server backup file, neither the user and the password, just the physical files in the "\data" folder, is there any way to do this?
The target server is in the same version of th old server.
Thanks.
Well as a test you could try:
pg_ctl start -D $DATA
Where pg_ctl comes from the target version and the $DATA is the the /data directory. You have not said how you came to have just a /data directory. If this came from an unclean shutdown or a corrupted drive the possibility exists that the server will not start.
UPDATE
To get around auth failure find pg_hba.conf and create or modify local connection to use trust method. For more info see pg_hba and trust. Then you should be able to connect like:
psql -d some_db -U postgres
Once in you can use ALTER ROLE to change password:
ALTER ROLE <role_name> WITH PASSWORD 'new_password';
I have a server that uses neo4j 3.5.x with docker. Now I want to move that database to another server.
This time I see that neo4j released 4.0. I just copied data folder which contains only graph.db
I run the script I used last time
sudo docker run --name vis --restart unless-stopped --log-opt max-size=50m --log-opt max-file=10 -p3001:7474 -p3002:7473 -p3003:3003 -d -v /data:/data -v /conf:/conf -v /logs:/logs --env NEO4J_AUTH=none neo4j
When I run this I see that I can reach it from 7474 which is fine. BUT it asks password to see the data. Though I didn't set a password WHY IT ASKS?
I tried everything possible like neo4j, 123, 1234, test or live it empty. none worked.
it gives error
neo4j-driver.chunkhash.bundle.js:1 WebSocket connection to 'ws://0.0.0.0:7687/' failed: Error in connection establishment: net::ERR_ADDRESS_INVALID
Is there a proper/robust way to import data between neo4j database servers? Can I use this https://neo4j.com/developer/kb/export-sub-graph-to-cypher-and-import/
If you go to the Neo4j desktop, and then select the graph. Open up Manage options. Then choose Open Terminal.
Once there you can use the database backup command. (Here is an example)
bin\neo4j-admin backup --backup-dir=c:/backup --name=graph.db-20200107
This will backup the database to the specified backup directory.
Then you can zip that backup directory, and then unzip the backup directory, and restore it on the new server.
(Here is an example)
bin\neo4j-admin restore --from=c:/backup/graph.db-20200107 --database=graph.db --force=true
Note: The 'graph.db-20200107' is an example of the name that you give the database backup. You can name it whatever you want.
-yyyguy
In an initialization script, I want to initialize a PostgreSQL directory, but don't need (and don't want) a running PostgreSQL server at this stage.
This would be a no-brainer if I just create the cluster (as user postgres):
initdb -D ...
However, I also need to create the PostgreSQL role, create the database and add some extensions (also as user postgres):
createuser someuser
createdb -O someuser somedb
echo 'CREATE EXTENSION xyz;' | psql somedb
The latter commands require a running PostgreSQL server. So this whole thing becomes quite messy:
initdb -D ...
# Start PostgreSQL server in background
... &
# Wait in a loop until PostgreSQL server is up and running
while ! psql -f /dev/null template1; do
sleep 0.5
done
createuser someuser
createdb -O someuser somedb
echo 'CREATE EXTENSION xyz;' | psql somedb
# Kill PostgreSQL server
kill ...
# Wait until the process is really killed
sleep 2
Especially the part that is waiting for the PostgreSQL server is never 100% reliable. I tried lots of variants and each of them failed in roughly 1 of 20 runs. Also, killing that process may not be 100% reliable in a simple shell script, let alone ensuring that it has stopped correctly.
I believe this is a standard problem that occurs in all use cases involving bootstrapping a server or preparing a VM image. So one would expect that in the year 2016, there should be some existing, realiable tooling for that. So my questions are:
Is there a simpler and more reliable way to achieve this?
For example, is there a way to run a PostgreSQL server in some special mode, where just starts up, executes certain SQL commands, and quits immediately after the last SQL command finished?
As a rough idea, is there something from the internal PostgreSQL test suite can be reused for this purpose?
You are looking for single-user mode.
If you start PostgreSQL like that, you are is a session connected as superuser that waits for SQL statements on standard input. As soon as you disconnect (with end-of-file), the server process is stopped.
So you could do it like this (with bash):
postgres --single -D /usr/local/pgsql/data postgres <<-"EOF"
CREATE USER ...;
CREATE DATABASE somedb ...;
EOF
postgres --single -D /usr/local/pgsql/data somedb <<-"EOF"
CREATE EXTENSION ...;
EOF
I want to install DB2 UDW in my machine for learning purpose but I am having a hard time configuring the local instance. Any help would be highly appreciated.
I installed DB2 express edition -c . I have selected all the default choices. I am trying to connect using IBM data Studio 4.1, In the "DB2 first Steps" GUI I have chosen to create SAMPLE Database. I am getting the below error
Creating database "SAMPLE" on path "C:"...
Existing "SAMPLE" database found...
The "-force" option was not specified...
Attempt to create the database "SAMPLE" failed
'db2sampl' processing complete.
I tried connecting from Data Studio using the following options
Database- SAMPLE
Port- 50000
host - localhost
Error I am getting
Explanation:
An attempt was made to access a database that was not found, has not been started, or does not support transactions.
User response:
Ensure that the specified database name exists in the system database directory. If the database name does not exist in the system database directory, either the database does not exist or the database name has not been cataloged. If needed, issue a db2start command and then resubmit the current command.
SQL4499N A fatal error occurred that resulted in a disconnect from the data source.
SQLSTATE: 08004
Problem is I am having zero knowledge in DB2. If I need to run db2start command from where I should run this? Please help
Probably the instance is not started.
Once you have installed DB2, you need to have an started instance in order to use any database. The instance could be created at the same time of the installation. You can verify which instances exist in your computer by issuing:
/opt/IBM/db2/V10.1/instance/db2ilist
The output should give you a set of users, where an instance has been configured.
You can change to that user and start the instance. For example if the user is db2inst1
su - db2inst1
db2start
Once the instance is started, you can now create a database and then connect to it.