Merge 46e5668f85 into 274a0e39d5

CMakeLists.txt

@@ -371,6 +371,7 @@ check_function_exists(backtrace_symbols HAVE_BACKTRACE_SYMBOLS)
 check_function_exists(pipe2 HAVE_PIPE2)
 check_function_exists(nice HAVE_NICE)
 check_function_exists(malloc_info HAVE_MALLOC_INFO)
+check_function_exists(malloc_trim HAVE_MALLOC_TRIM)
 check_function_exists(pthread_set_name_np HAVE_PTHREAD_SET_NAME_NP)
 check_function_exists(pthread_setname_np HAVE_PTHREAD_SETNAME_NP)
 check_library_exists(dl dladdr "dlfcn.h" HAVE_DLADDR)

config.h.cmake

@@ -9,6 +9,7 @@
 #cmakedefine HAVE_CXXABI_H
 #cmakedefine HAVE_NICE
 #cmakedefine HAVE_MALLOC_INFO
+#cmakedefine HAVE_MALLOC_TRIM
 #cmakedefine HAVE_PTHREAD_SET_NAME_NP
 #cmakedefine HAVE_PTHREAD_SETNAME_NP
 #cmakedefine HAVE_EDITLINE

doc/12-icinga2-api.md

@@ -2594,6 +2594,40 @@ but the raw XML output from `malloc_info(3)`. See also the
 </malloc>
 ```
 
+### Memory Usage Reduction <a id="icinga2-api-memory-trim"></a>
+
+The GNU libc function `malloc_trim(3)` attempts to release free memory
+from the main heap arena of Icinga 2 itself. You can call it directly
+by sending a `POST` request to the URL endpoint `/v1/debug/malloc_trim`.
+
+The following parameters may be specified
+(either as URL parameters or in a JSON-encoded message body):
+
+  Parameter | Type   | Description
+  ----------|--------|-------------
+  pad       | Number | **Optional.** How many heap bytes to preserve, so the next `malloc(3)` call doesn't need to re-allocate memory again via `sbrk(2)`. Defaults to 0.
+
+The [API permission](12-icinga2-api.md#icinga2-api-permissions) `debug` is required.
+
+Example:
+
+```bash
+curl -k -s -S -i -u root:icinga -H 'Accept: application/json' \
+ -X POST 'https://localhost:5665/v1/debug/malloc_trim?pad=1'
+```
+
+```json
+{
+    "results": [
+        {
+            "code": 200.0,
+            "malloc_trim": 1.0,
+            "status": "Some memory was released back to the system."
+        }
+    ]
+}
+```
+
 ## API Clients <a id="icinga2-api-clients"></a>
 
 After its initial release in 2015, community members

lib/remote/CMakeLists.txt

@@ -34,6 +34,7 @@ set(remote_SOURCES
   jsonrpc.cpp jsonrpc.hpp
   jsonrpcconnection.cpp jsonrpcconnection.hpp jsonrpcconnection-heartbeat.cpp jsonrpcconnection-pki.cpp
   mallocinfohandler.cpp mallocinfohandler.hpp
+  malloctrimhandler.cpp malloctrimhandler.hpp
   messageorigin.cpp messageorigin.hpp
   modifyobjecthandler.cpp modifyobjecthandler.hpp
   objectqueryhandler.cpp objectqueryhandler.hpp

lib/remote/malloctrimhandler.cpp

@@ -0,0 +1,84 @@
+/* Icinga 2 | (c) 2024 Icinga GmbH | GPLv2+ */
+
+#include "remote/filterutility.hpp"
+#include "remote/httputility.hpp"
+#include "remote/malloctrimhandler.hpp"
+#include <boost/lexical_cast.hpp>
+#include <cstddef>
+
+#ifdef HAVE_MALLOC_TRIM
+#	include <malloc.h>
+#endif /* HAVE_MALLOC_TRIM */
+
+using namespace icinga;
+
+REGISTER_URLHANDLER("/v1/debug/malloc_trim", MallocTrimHandler);
+
+bool MallocTrimHandler::HandleRequest(
+	AsioTlsStream&,
+	const ApiUser::Ptr& user,
+	boost::beast::http::request<boost::beast::http::string_body>& request,
+	const Url::Ptr& url,
+	boost::beast::http::response<boost::beast::http::string_body>& response,
+	const Dictionary::Ptr& params,
+	boost::asio::yield_context&,
+	HttpServerConnection&
+)
+{
+	namespace http = boost::beast::http;
+
+	if (url->GetPath().size() != 3) {
+		return false;
+	}
+
+	if (request.method() != http::verb::post) {
+		return false;
+	}
+
+	auto rawPad (HttpUtility::GetLastParameter(params, "pad"));
+	size_t pad = 0;
+
+	if (rawPad.GetType() != ValueEmpty) {
+		try {
+			pad = boost::lexical_cast<size_t>(rawPad);
+		} catch (const std::exception&) {
+			HttpUtility::SendJsonError(response, params, 400,
+				"Invalid 'pad' specified. An integer [0," BOOST_PP_STRINGIZE(SIZE_MAX) "] is required.");
+
+			return true;
+		}
+	}
+
+	FilterUtility::CheckPermission(user, "debug");
+
+#ifndef HAVE_MALLOC_TRIM
+	HttpUtility::SendJsonError(response, params, 501, "malloc_trim(3) not available.");
+#else /* HAVE_MALLOC_TRIM */
+	Dictionary::Ptr result1;
+	auto ret (malloc_trim(pad));
+
+	if (ret) {
+		result1 = new Dictionary({
+			{ "code", 200 },
+			{ "malloc_trim", ret },
+			{ "status", "Some memory was released back to the system." }
+		});
+	} else {
+		result1 = new Dictionary({
+			{ "code", 503 },
+			{ "malloc_trim", ret },
+			{ "status", "It was not possible to release any memory." }
+		});
+
+		response.result(http::status::service_unavailable);
+	}
+
+	Dictionary::Ptr result = new Dictionary({
+		{ "results", new Array({ result1 }) }
+	});
+
+	HttpUtility::SendJsonBody(response, params, result);
+#endif /* HAVE_MALLOC_TRIM */
+
+	return true;
+}

lib/remote/malloctrimhandler.hpp

@@ -0,0 +1,27 @@
+/* Icinga 2 | (c) 2024 Icinga GmbH | GPLv2+ */
+
+#pragma once
+
+#include "remote/httphandler.hpp"
+
+namespace icinga
+{
+
+class MallocTrimHandler final : public HttpHandler
+{
+public:
+	DECLARE_PTR_TYPEDEFS(MallocTrimHandler);
+
+	bool HandleRequest(
+		AsioTlsStream& stream,
+		const ApiUser::Ptr& user,
+		boost::beast::http::request<boost::beast::http::string_body>& request,
+		const Url::Ptr& url,
+		boost::beast::http::response<boost::beast::http::string_body>& response,
+		const Dictionary::Ptr& params,
+		boost::asio::yield_context& yc,
+		HttpServerConnection& server
+	) override;
+};
+
+}