Impala client packages

Learn about how to install the Impala shell, a command-line interface for running SQL queries, and the necessary development files for building custom C++ User-Defined Functions (UDFs).

Installing the Impala Shell Client

The Impala shell is available as a client package for various operating systems, such as RPMs for Red Hat/CentOS/SUSE and DEBs for Ubuntu. It can be installed using native package managers and supports multiple connection scenarios, including various security protocols.

Prerequisites: You must ensure that the official repository for your operating system is properly configured on your target host.

Install the RPM.

For Red Hat / CentOS 7:
```
sudo yum install impala-shell-client
```
For Red Hat 9:
```
sudo dnf install impala-shell-client
```
For SUSE 12 / SUSE 15:
```
sudo zypper install impala-shell-client
```

For Ubuntu 20 / Ubuntu 22:

sudo apt-get update
sudo apt-get install impala-shell-client

Verify the installation:

which impala-shell

impala-shell --version

Connect to an Impala Coordinator.
- If the client node is within the cluster:
  1. Find the connection string example from the Status tab on your Impala cluster page within Cloudera Manager.
  2. Run the shell command on the client node, replacing <impala-coordinator-host> with your coordinator's hostname:
```
impala-shell -i <impala-coordinator-host> -d default
```
    Result:
```
Starting Impala Shell with no authentication using Python <python-version> Opened TCP connection to <impala-coordinator-host>:21050 Connected to <impala-coordinator-host>:21050 Server version: impalad version <build-version> Query: use `default` *********************************************************************************** Welcome to the Impala shell. ... You can run a single query from the command line using the '-q' option. *********************************************************************************** Query: use `default` [<impala-coordinator-host>:21050] default>
```
  3. If Kerberos is enabled, ensure a valid Kerberos ticket has been obtained for the Impala user on the client node. For more, see Enabling Kerberos Authentication for CDP.
  4. If SSL is enabled, ensure that the CA certificate file exists at the configured path on the client node.
- If the client node is outside the cluster:
  1. Without SSL and Kerberos:
    If the Impala cluster does not use SSL or kerberos, you can connect directly with a simple command:
```
impala-shell -i <impala-coordinator-host> -d default
```
  2. With SSL and Kerberos:
    If SSL and kerberos are enabled, direct access to Impala from outside the Cloudera Manager cluster may not be possible due to security restrictions.
  3. Using Knox as a gateway (if enabled):
    If Knox is available, you can connect through Knox + LDAP authentication using the following command:
```
impala-shell -i <impala-coordinator-host>:8443 \
  --protocol=hs2-http \
  --ssl \
  -l -u <username> \
  --ldap_password_cmd='echo -n <password>' \
  --http_path=gateway/cdp-proxy-api/impala
```
    This approach uses HS2 HTTP protocol through Knox gateway, with LDAP credentials and SSL encryption.

Installing the Impala UDF Development Client

To develop Impala User-Defined Functions (UDFs) in C++, you need to install the Impala development headers and library files. The following steps guide you through downloading, installing, and verifying these files on your target host.

Prerequisites: You must ensure that the official repository for your operating system is properly configured on your target host.

Install the downloaded package.

For Red Hat / CentOS 7

sudo yum install impala-udf-devel-client

For Red Hat 9

sudo dnf install impala-udf-devel-client

For SUSE 12 / SUSE 15

sudo zypper install impala-udf-devel-client

For Ubuntu 20 / Ubuntu 22

sudo apt-get update
sudo apt-get install impala-udf-dev-client

Verify the installation by checking for the presence of UDF headers and library files.
```
ls /usr/include/impala_udf/udf.h
ls /usr/lib64/libImpalaUdf*
# Or, on some systems:
ls /usr/lib/libImpalaUdf*
```
Result: The Impala UDF development headers (/usr/include/impala_udf/udf.h) and library files (/usr/lib64/libImpalaUdf*) are successfully installed.

To learn how to use these headers and libraries to develop Impala UDFs in C++, see User-defined functions (UDFs)