Apache Edgent is designed as a modular SDK so that only required code needs to be deployed to a device to reduce footprint.
The downside to this is that Edgent' distribution contains main JARs, at least one per module.
JAR layout in a distribution
The core JARs in a distribution are under lib and their dependent third-party JARs are under ext.
Optional modules are under category/module, for example connectors/http with their Edgent & third-party JARs in the sub-directories lib & ext respectively, e.g. connectors/http/lib and connectors/http/ext.
Note all JAR sizes are at the time of writing, and are subject to change.
Core JARs
| Directory | Size (bytes) |
|---|---|
| lib | 188K |
| ext | 588K |
The only optional JAR in the core set is for the DevelopmentProvider : org.apache.edgent.providers.development.jar. This is only 4K so removing it from you distribution to a device is a minimal saving.
Connector Modules
| Connector | Size (bytes) | Notes |
|---|---|---|
| connectors/file | 40K | |
| connectors/http | 1.2M | |
| connectors/iot | 16K | |
| connectors/iotf | 3.0M | requires connectors/iot |
| connectors/jdbc | 24K | |
| connectors/kafka | 13M | |
| connectors/mqtt | 204K | requires connectors/iot |
To reduce footprint the simpliest approach is to remove the modules not needed in a device deployment. Note the biggest saving is removing the Kafka connector, which is typically an enterprise connector rather than an IoT one.
Analytic Modules
| Analytic | Size (bytes) | Notes |
|---|---|---|
| analytics/math3 | 2.0M | |
| analytics/sensors | 16K |
Util Modules
| Utility | Size (bytes) | Notes |
|---|---|---|
| utils/metrics | 24K |
Other Modules
| Modules | Size (bytes) | Notes |
|---|---|---|
| console | 1.8M | Required by development provider |
| samples | 648K | Sample applications, typically not required for real applications |
| scripts | 160K | Scripts for sample applications, typically not required for real applications |
Example Device Deployment
Here's an example set of JARs for use by a Edgent application on a device that uses IBM Watson IoT Platform to communicate with back end systems, JDBC for a local data store and all the analytics Edgent currently provides.
| Modules | Size (bytes) | Notes |
|---|---|---|
| core lib | 184K | Development provider not included |
| core ext | 588K | |
| connectors/iot | 16K | |
| connectors/iotf | 3.0M | requires connectors/iot |
| connectors/jdbc | 24K | |
| analytics/math3 | 2.0M | |
| analytics/sensors | 16K | |
| Total | ~5.7M | A 75% space reduction compared to the full java8 distribution size of 23.0M |