In some systems the control pool consists of a single machine—referred to as the "controller." This also hosts the web and data aggregation services so that there is no separate web pool. At larger scales a web pool of additional machines can be added to increase capacity for web and data aggregation services, with the "controller" remaining on a separate machine.
Operating system—one of the following Linux distributions/versions:
Operating system—Linux versions as above, or Windows 7 or later.
Required on Windows:
On Linux, the latest JDK 8 and Python 2.x are installed on the worker host machine by LGTM if they are not found.
† Semmle recommends that you use solid-state drives (SSDs) rather than hard disk drives (HDDs) for all of the machines, in both the control pool and the work pool. It is strongly recommended that you use an SSD for the "controller" machine, as files are served from here to all other cluster machines.
During installation, upgrade and configuration processes, root access is required for each machine.
Virtual machines (for example, using VMWare, Xen, or KVM) or physical machines are both suitable for the pools of machines. The terms "machines" and "virtual machines" are used interchangeably in the documentation.
The computational power required for the work pool depends on the number of projects to analyze, their size, build times (for compiled languages such as Java), and the average commit frequency.
As this information is usually difficult to ascertain in advance, it makes sense to plan for an incremental deployment based on the following information:
- Minimum deployment size for LGTM Enterprise
- Hardware requirements at scale
- Incrementally adding capacity
LGTM Enterprise uses the following third-party software. If these resources are not found on the relevant machines during installation of LGTM Enterprise, they are automatically installed.
- Java JRE 8 (if necessary, OpenJDK 8 will be installed)
- Python 2
- PostgreSQL 9.5 or later
- RabbitMQ Server
- Solr 7.5.0 (bundled with LGTM)
- Minio release 2019-05-02T19-07-09Z (bundled with LGTM)
With the exception of Solr and Minio (which are supplied within the LGTM distribution), the version number of the software that's installed depends on what the latest available version is when the installation is performed. Any dependencies are also installed.
Access to third-party packages during installation
The simplest way to install LGTM Enterprise is to enable internet access and to run the installation script supplied with the application. This enables the installer to download and install the required packages from their official online package repositories using the standard tools available in your Linux distribution. If you're using Red Hat Enterprise or CentOS, this will require access to the EPEL (Extra Packages for Enterprise Linux) repository. Once LGTM has been deployed, internet access can be closed down.
If internet access is not available, you can do either of the following:
Configure the machine so that it can access an internally hosted mirror that contains these package repositories and their dependencies. The installer will download and install the required packages from your internal mirror.
For installations on Red Hat or CentOS: Extract the third-party dependencies pack before you run the installer. Details for doing this are included in the installation instructions.