Hera multiplexes connections for MySQL and Oracle databases. It supports sharding the databases for horizontal scaling.
Hera is Data Access Gateway for databases and is a key enabler for scaling and improving availability databases.
- It Protects the database from resource exhaustion by evicting poorly performing queries,
- Intelligently routes read/write traffic appropriately for better load balancing,
- Improves tolerance to database outages,
- Provides high performance secured connections between applications and Hera
- Provides domain agnostic database sharding for horizontal database scaling.
- Automatic transaction application failover between replica databases
- And many more site resiliency features.
You can build mux using either Docker or manual build.
For development, the following docker commands can help get started
docker run --network host --name mysql-11 -e MYSQL_ROOT_PASSWORD=62-AntHill -d mysql:latest
docker exec -it mysql-11 bash -c 'echo "create database testschema;" | mysql -u root -h 127.0.0.1 -p62-AntHill'
cd hera/tests/devdocker
mkdir -p src/github.com/paypal/hera
rsync -av --exclude tests/devdocker ../.. src/github.com/paypal/hera
docker build -t hera-oss .
docker run -it --rm --name testRunHeraOss --network host -e password=62-AntHill hera-oss
To test it, in a separate terminal:
docker exec -it testRunHeraOss /bin/bash
cd /go/src
go run github.com/paypal/hera/client/gosqldriver/tls/example/sample_main.go
The following sections explain the process for manually building mux without Docker. We only tested on RedHat and Ubuntu.
- Install Go 1.10+.
- Install MySQL or Oracle(https://www.oracle.com/index.html).
- Install the MySQL driver and the Oracle driver
- Install Oracle instant client
-
Navigate to the working directory.
cd $WORKSPACE export GOPATH=$WORKSPACE
-
Option 1
Clone the source code from github
git clone git@github.com:paypal/hera src/github.com/paypal/hera
Option 2
(a) GO 1.12 is prerequisite
(b) export GO111MODULE=on ( to enable the go mod feature)
go get github.com/paypal/hera
-
Install the dependencies: MySQL and Oracle driver
go get gopkg.in/goracle.v2 go get github.com/go-sql-driver/mysql
-
Build server binaries
go install github.com/paypal/hera/mux github.com/paypal/hera/worker/mysqlworker github.com/paypal/hera/worker/oracleworker
-
Build Go test client
go install github.com/paypal/hera/tests/e2e/client
-
Build Java test client under the client/java directory
-
Build the C++ oracleworker
cd worker/cppworker/worker make -f ../build/makefile19
To run mux there is minimal configuration required. Please see examples for running with MySQL or Oracle. The main configuration file is hera.txt, which must contain the TCP port where the server listens and the number of workers. The user name, password and the data source are passsed via environment parameters.
# the proxy executable
ln -s $GOPATH/bin/mux .
# the MySQL worker
ln -s $GOPATH/bin/mysqlworker mysqlworker
# to use the Oracle worker use oracleworker instead of mysqlworker
# create the configuration file with the required configuration
echo 'bind_ip=127.0.0.1' > hera.txt
echo 'bind_port=11111' >> hera.txt
echo 'opscfg.hera.server.max_connections=2' >> hera.txt
# if using mysql run this
# echo 'database_type=mysql' >> hera.txt
# create minimal CAL configuration, needed by ops config
echo 'cal_pool_name=stage_hera' > cal_client.txt
# the database user name
export username='user'
# the database password
export password='pass'
# the data source
export TWO_TASK='tcp(127.0.0.1:3306)/myschema'
# for Oracle the datasource can be like '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=hostname)
# (PORT=12345)))(CONNECT_DATA=(SERVICE_NAME=sn)))'.
# for Oracle only add to LD_LIBRARY_PATH environment variable the path to the shared libraries of the
# Oracle instant client
# start
./mux --name hera-test
For details about the parameters see configuration
There is a Java client implemented as JDBC driver. Please see the documentation for how to install and use it.
There is also a Go client implemented as SQL driver. Please see the example.
Hera is licensed under Apache 2.0.