By default, AppScope is configured to connect to an instance of Cribl Edge (docs) running on the same host. Cribl Edge, in turn, connects to Cribl LogStream over the network. This arrangement can support scaling to large numbers of scoped processes.
AppScope will connect with Cribl Edge when the
cribl backend is enabled with the
edge transport type. These are default settings for the AppScope library, which is best suited for the kinds of longer-running, planned monitoring procedures that tend to scale, and where the AppScope-Cribl Edge combination excels.
The CLI, by contrast, writes to the local filesystem by default; and the CLI is best suited for ad hoc exploration that's less likely to scale to large numbers of scoped processes.
To define a connection to Cribl Edge with the AppScope library, just set the
SCOPE_CRIBL environment variable to
LD_PRELOAD=./libscope.so SCOPE_CRIBL=edge ls -al
The number of scoped processes can become very high in two kinds of situations:
In either case, it can help when AppScope connects to Cribl Edge on the same host, and Cribl Edge then connects to Cribl LogStream over the network.
To understand why this is, consider these facts:
This results in dramatically lower numbers of network connections needed than if AppScope connected to LogStream over the network without Cribl Edge as a proxy. Each network connection requires a port, and a large number of connections could exhaust the supply of ports available on the LogStream host.
Sending data through Cribl Edge has other benefits: Cribl Edge is capable of filtering, aggregating, and reducing data in the same manner as Cribl LogStream, and it can be efficient to perform these operations on the data before sending it over the wire.
To define a TLS-encrypted connection to LogStream Cloud, just set the
SCOPE_CRIBL_CLOUD environment variable, specifying a transport type, a host name or IPv4 address, and a port number.
By default, LogStream Cloud instances have port
10090 configured to use TLS over TCP, and a built-in AppScope Source to receive data from AppScope. You can change the AppScope Source configuration, or create additional AppScope Sources, as needed.
When AppScope establishes a LogStream connection, this sets several AppScope configuration parameters, some of which override settings in any configuration file or environment variable.
These overrides include:
warningif originally configured as
Any configuration override is logged to AppScope's default log file.
If you have events or metrics enabled (or disabled), they retain this setting. (Before v.1.0.0, both would be set to enabled, as an override). You still have control via environment variables or the config file.
To define an unencrypted connection to a LogStream Cloud instance, set the
SCOPE_CRIBL environment variable (not
SCOPE_CRIBL_CLOUD) and specify port
An on-prem instance of LogStream has an AppScope Source built in. However, by default:
To connect from AppScope, you'll need to configure the AppScope Source in LogStream. This includes enabling the Source; configuring it to listen on the desired port; and, enabling and configuring TLS if desired.
Then, to define a connection to the on-prem LogStream instance, set