This article is intended for anyone currently using the 4.3.7 (or earlier) or 4.4.0 version of the AppDynamics C++/C SDK, which uses a separate Proxy (JVM) task, and who wishes to upgrade to the 4.4.1 libagent-based (proxy-less) version of the SDK.
Contents:
Why upgrade?
There are numerous reasons to do so, the most important is that this newer version represents the current and future SDK architecture. The next reason is resource consumption. The older proxy-based version uses a stand-alone JVM, which has a minimum 300M footprint, all of the additional CPU consumption that a JVM requires, the use of socket files (which consume up to 8K worth of open file descriptors), not to mention the necessary coordination of user IDs and file permissions between the Agent and Proxy tasks, and any additional SELinux policy concerns that that introduces.
These reasons all justify moving to the newer SDK architecture, and we strongly encourage you to do so.
Differences between versions
The differences between the old and new formats, although not 100% ABI compatible, will be quite easy to navigate. The major differences in porting to the new version is that the configuration-structure initialization. In the previous version, you needed to allocate the structure, then initialize each field. In the newer version, the structure is already allocated, you simply call setter functions to fill in the fields you wish to set.
Presuming you were declaring the fields as const chars (in both versions).
For example:
const char APP_NAME[] = "SampleC";
const char TIER_NAME[] = "SampleCTier1";
const char NODE_NAME[] = "SampleCNode1";
const char CONTROLLER_HOST[] = "osxlttyu";
const int CONTROLLER_PORT = 8080;
const char CONTROLLER_ACCOUNT[] = "customer1";
const char CONTROLLER_ACCESS_KEY[] = "SJ5b2m7d1$354";
const int CONTROLLER_USE_SSL = 0;
In the older versions (4.2 through 4.3.7 and 4.4.0) within your own code you would declare and allocate an appd_config struct and assign the settings to it.
For example:
appd_config cfg;
appd_config_init(&cfg);
cfg.app_name = (char*)APP_NAME;
cfg.tier_name = (char*)TIER_NAME;
cfg.node_name = (char*)NODE_NAME;
cfg.controller.host = (char*)CONTROLLER_HOST;
cfg.controller.port = CONTROLLER_PORT;
cfg.controller.account = (char*)CONTROLLER_ACCOUNT;
cfg.controller.access_key = (char*)CONTROLLER_ACCESS_KEY;
cfg.controller.use_ssl = CONTROLLER_USE_SSL;
#ifdef _WIN32
cfg.appd_proxy_config.tcp_control_port = PROXY_CTRL_PORT;
cfg.appd_proxy_config.tcp_request_port = PROXY_REQ_PORT;
cfg.appd_proxy_config.tcp_reporting_port = PROXY_REP_PORT;
#endif
cfg.init_timeout_ms = 0;
In the newer SDK (4.3.8 & 4.4.1 and later versions) you would call an initialization routine (which zeros the internally stored structure and returns its address) then call setter methods for each field in that structure.
For example:
appd_config* cfg = appd_config_init(); // appd_config_init() resets the configuration object and pass back an handle/pointer
appd_config_set_app_name(cfg, APP_NAME);
appd_config_set_tier_name(cfg, TIER_NAME);
appd_config_set_node_name(cfg, NODE_NAME);
appd_config_set_controller_host(cfg, CONTROLLER_HOST);
appd_config_set_controller_port(cfg, CONTROLLER_PORT);
appd_config_set_controller_account(cfg, CONTROLLER_ACCOUNT);
appd_config_set_controller_access_key(cfg, CONTROLLER_ACCESS_KEY);
appd_config_set_controller_use_ssl(cfg, CONTROLLER_USE_SSL);
New features
There are a few other newer features within the SDK to be aware of. The first is that you no longer need to start the proxy task, as this is done automatically with the call to appd_sdk_init(), which will spawn a limited number of tasks to handle collating BTs, Metrics, Snapshots, etc., and communicate them to the Controller (all within the same user ID as the calling method).
Additionally, there is no longer any need to worry about file descriptors (we no longer use sockets for the C++/libagent SDK and the NodeJS/libagent-based Agent), although this is still the case for the Apache, Python, PHP, and other dynamics languages agents. A libagent (proxy-less) version of them are all on our roadmap, speak with your AppDynamics Account Manager for details on when they might be available.
And, as always, if you are having any problems using the C++/C libagent (proxy-less) based SDK, please feel free to submit a
help request to us.
