[v24.2.x] pandaproxy: add max memory check for incoming requests

src/v/pandaproxy/probe.cc

@@ -104,4 +104,79 @@ void probe::setup_public_metrics() {
          .aggregate(aggregate_labels)});
 }
 
+server_probe::server_probe(
+  server::context_t& ctx, const ss::sstring& group_name)
+  : _ctx(ctx)
+  , _group_name(group_name)
+  , _metrics()
+  , _public_metrics() {
+    setup_metrics();
+}
+
+void server_probe::setup_metrics() {
+    namespace sm = ss::metrics;
+
+    auto setup_common = [this]<typename MetricDef>() {
+        const auto usage = [](const size_t current, const size_t max) {
+            constexpr double divide_by_zero = -1.;
+            constexpr double invalid_values = -2.;
+            if (max == 0) {
+                return divide_by_zero;
+            }
+            if (current > max) {
+                return invalid_values;
+            }
+            const auto max_d = static_cast<double>(max);
+            const auto current_d = static_cast<double>(current);
+            return (max_d - current_d) / max_d;
+        };
+
+        std::vector<MetricDef> defs;
+        defs.reserve(3);
+        defs.emplace_back(
+          sm::make_gauge(
+            "inflight_requests_usage_ratio",
+            [this, usage] {
+                return usage(_ctx.inflight_sem.current(), _ctx.max_inflight);
+            },
+            sm::description(ssx::sformat(
+              "Usage ratio of in-flight requests in the {}", _group_name)))
+            .aggregate({}));
+        defs.emplace_back(
+          sm::make_gauge(
+            "inflight_requests_memory_usage_ratio",
+            [this, usage] {
+                return usage(_ctx.mem_sem.current(), _ctx.max_memory);
+            },
+            sm::description(ssx::sformat(
+              "Memory usage ratio of in-flight requests in the {}",
+              _group_name)))
+            .aggregate({}));
+        defs.emplace_back(
+          sm::make_gauge(
+            "queued_requests_memory_blocked",
+            [this] { return _ctx.mem_sem.waiters(); },
+            sm::description(ssx::sformat(
+              "Number of requests queued in {}, due to memory limitations",
+              _group_name)))
+            .aggregate({}));
+        return defs;
+    };
+
+    if (!config::shard_local_cfg().disable_metrics()) {
+        _metrics.add_group(
+          _group_name,
+          setup_common
+            .template operator()<ss::metrics::impl::metric_definition_impl>(),
+          {},
+          {});
+    }
+
+    if (!config::shard_local_cfg().disable_public_metrics()) {
+        _public_metrics.add_group(
+          _group_name,
+          setup_common.template operator()<ss::metrics::metric_definition>());
+    }
+}
+
 } // namespace pandaproxy

src/v/pandaproxy/probe.h

@@ -12,6 +12,7 @@
 #pragma once
 
 #include "metrics/metrics.h"
+#include "pandaproxy/server.h"
 #include "utils/log_hist.h"
 
 #include <seastar/core/metrics_registration.hh>
@@ -82,4 +83,22 @@ class probe {
     metrics::public_metric_groups _public_metrics;
 };
 
+class server_probe {
+public:
+    server_probe(server::context_t& ctx, const ss::sstring& group_name);
+    server_probe(const server_probe&) = delete;
+    server_probe& operator=(const server_probe&) = delete;
+    server_probe(server_probe&&) = delete;
+    server_probe& operator=(server_probe&&) = delete;
+    ~server_probe() = default;
+
+private:
+    void setup_metrics();
+
+    server::context_t& _ctx;
+    const ss::sstring& _group_name;
+    metrics::internal_metric_groups _metrics;
+    metrics::public_metric_groups _public_metrics;
+};
+
 } // namespace pandaproxy

src/v/pandaproxy/reply.h

@@ -65,6 +65,10 @@ inline ss::http::reply& set_reply_too_many_requests(ss::http::reply& rep) {
       .add_header("Retry-After", "0");
 }
 
+inline ss::http::reply& set_reply_payload_too_large(ss::http::reply& rep) {
+    return rep.set_status(ss::http::reply::status_type::payload_too_large);
+}
+
 inline std::unique_ptr<ss::http::reply> reply_unavailable() {
     auto rep = std::make_unique<ss::http::reply>(ss::http::reply{});
     set_reply_unavailable(*rep);

src/v/pandaproxy/rest/proxy.cc

@@ -113,7 +113,7 @@ proxy::proxy(
   , _inflight_config_binding(config::shard_local_cfg().max_in_flight_pandaproxy_requests_per_shard.bind())
   , _client(client)
   , _client_cache(client_cache)
-  , _ctx{{{{}, _mem_sem, _inflight_sem, {}, smp_sg}, *this},
+  , _ctx{{{{}, max_memory, _mem_sem, _inflight_config_binding(), _inflight_sem, {}, smp_sg}, *this},
         {config::always_true(), config::shard_local_cfg().superusers.bind(), controller},
         _config.pandaproxy_api.value()}
   , _server(
@@ -126,8 +126,11 @@ proxy::proxy(
       json::serialization_format::application_json)
   , _ensure_started{[this]() { return do_start(); }}
   , _controller(controller) {
-    _inflight_config_binding.watch(
-      [this]() { _inflight_sem.set_capacity(_inflight_config_binding()); });
+    _inflight_config_binding.watch([this]() {
+        const size_t capacity = _inflight_config_binding();
+        _inflight_sem.set_capacity(capacity);
+        _ctx.max_inflight = capacity;
+    });
 }
 
 ss::future<> proxy::start() {

src/v/pandaproxy/schema_registry/service.cc

@@ -612,7 +612,7 @@ service::service(
       config::shard_local_cfg()
         .max_in_flight_schema_registry_requests_per_shard.bind())
   , _client(client)
-  , _ctx{{{}, _mem_sem, _inflight_sem, {}, smp_sg}, *this}
+  , _ctx{{{}, max_memory, _mem_sem, _inflight_config_binding(), _inflight_sem, {}, smp_sg}, *this}
   , _server(
       "schema_registry", // server_name
       "schema_registry", // public_metric_group_name
@@ -630,8 +630,11 @@ service::service(
       config::always_true(),
       config::shard_local_cfg().superusers.bind(),
       controller.get()} {
-    _inflight_config_binding.watch(
-      [this]() { _inflight_sem.set_capacity(_inflight_config_binding()); });
+    _inflight_config_binding.watch([this]() {
+        const size_t capacity = _inflight_config_binding();
+        _inflight_sem.set_capacity(capacity);
+        _ctx.max_inflight = capacity;
+    });
 }
 
 ss::future<> service::start() {

src/v/pandaproxy/server.cc

@@ -28,6 +28,7 @@
 
 #include <charconv>
 #include <exception>
+#include <memory>
 
 namespace pandaproxy {
 
@@ -104,6 +105,12 @@ struct handler_adaptor : ss::httpd::handler_base {
             co_return std::move(rp.rep);
         }
         auto req_size = get_request_size(*rq.req);
+        if (req_size > _ctx.max_memory) {
+            set_reply_payload_too_large(*rp.rep);
+            rp.mime_type = _exceptional_mime_type;
+            set_and_measure_response(rp);
+            co_return std::move(rp.rep);
+        }
         auto sem_units = co_await ss::get_units(_ctx.mem_sem, req_size);
         if (_ctx.as.abort_requested()) {
             set_reply_unavailable(*rp.rep);
@@ -150,7 +157,8 @@ server::server(
   , _api20(std::move(api20))
   , _has_routes(false)
   , _ctx(ctx)
-  , _exceptional_mime_type(exceptional_mime_type) {
+  , _exceptional_mime_type(exceptional_mime_type)
+  , _probe{} {
     _api20.set_api_doc(_server._routes);
     _api20.register_api_file(_server._routes, header);
     _api20.add_definitions_file(_server._routes, definitions);
@@ -195,6 +203,9 @@ ss::future<> server::start(
   const std::vector<model::broker_endpoint>& advertised) {
     _server._routes.register_exeption_handler(
       exception_replier{ss::sstring{name(_exceptional_mime_type)}});
+
+    _probe = std::make_unique<server_probe>(_ctx, _public_metrics_group_name);
+
     _ctx.advertised_listeners.reserve(endpoints.size());
     for (auto& server_endpoint : endpoints) {
         auto addr = co_await net::resolve_dns(server_endpoint.address);
@@ -234,13 +245,18 @@ ss::future<> server::start(
         }
         co_await _server.listen(addr, cred);
     }
+
     co_return;
 }
 
 ss::future<> server::stop() {
-    return _pending_reqs.close()
-      .finally([this]() { return _ctx.as.request_abort(); })
-      .finally([this]() mutable { return _server.stop(); });
+    return _pending_reqs.close().finally([this]() {
+        _ctx.as.request_abort();
+        _probe.reset(nullptr);
+        return _server.stop();
+    });
 }
 
+server::~server() noexcept = default;
+
 } // namespace pandaproxy

src/v/pandaproxy/server.h

@@ -26,6 +26,7 @@
 #include <seastar/core/future.hh>
 #include <seastar/core/gate.hh>
 #include <seastar/core/shared_ptr.hh>
+#include <seastar/core/sstring.hh>
 #include <seastar/http/api_docs.hh>
 #include <seastar/http/handlers.hh>
 #include <seastar/http/httpd.hh>
@@ -40,6 +41,8 @@
 
 namespace pandaproxy {
 
+class server_probe;
+
 inline ss::shard_id user_shard(const ss::sstring& name) {
     auto hash = xxhash_64(name.data(), name.length());
     return jump_consistent_hash(hash, ss::smp::count);
@@ -69,7 +72,9 @@ class server {
 public:
     struct context_t {
         std::vector<net::unresolved_address> advertised_listeners;
+        size_t max_memory;
         ssx::semaphore& mem_sem;
+        size_t max_inflight;
         adjustable_semaphore& inflight_sem;
         ss::abort_source as;
         ss::smp_service_group smp_sg;
@@ -103,9 +108,9 @@ class server {
     };
 
     server() = delete;
-    ~server() = default;
+    ~server() noexcept;
     server(const server&) = delete;
-    server(server&&) noexcept = default;
+    server(server&&) noexcept = delete;
     server& operator=(const server&) = delete;
     server& operator=(server&&) = delete;
 
@@ -135,6 +140,7 @@ class server {
     bool _has_routes;
     context_t& _ctx;
     json::serialization_format _exceptional_mime_type;
+    std::unique_ptr<server_probe> _probe;
 };
 
 template<typename service_t>

tests/rptest/tests/pandaproxy_test.py

@@ -35,12 +35,15 @@
 from rptest.services import tls
 from rptest.utils.utf8 import CONTROL_CHARS_MAP
 from typing import Optional, List, Dict, Union
+from rptest.utils.mode_checks import skip_debug_mode
 
 
 def create_topic_names(count):
     return list(f"pandaproxy-topic-{uuid.uuid4()}" for _ in range(count))
 
 
+PAYLOAD_TOO_LARGE_HTTP_ERROR_CODE = 413
+
 HTTP_GET_BROKERS_HEADERS = {
     "Accept": "application/vnd.kafka.v2+json",
     "Content-Type": "application/vnd.kafka.v2+json"
@@ -1284,6 +1287,66 @@ def test_invalid_topics_fetch(self):
         assert sc_res.json(
         )["message"] == f'Invalid parameter \'topic_name\' got \'{topic_name.translate(CONTROL_CHARS_MAP)}\''
 
+    #Memory tracking is disabled in debug
+    @skip_debug_mode
+    @cluster(num_nodes=3)
+    def test_topic_produce_request_too_big(self):
+        """
+        Create a topic and post a request larger than the total available memory.
+        """
+
+        self.redpanda.set_resource_settings(
+            ResourceSettings(memory_mb=256, num_cpus=1))
+        self.redpanda.start()
+
+        name = create_topic_names(1)[0]
+
+        self.logger.info("Generating request larger than the available memory")
+        value = {
+            "value":
+            ("TWVzc2FnZSBTdGFydC4gVXNpbmcgYSBsb25nIHNlbnRlbmNlIHRvIGJlIGFibGUgdG8gcmVhY2ggdGhlIGF2YWlsYWJsZSB"
+             "tZW1vcnkgbGltaXQgd2l0aG91dCBoYXZpbmcgdG8gdXNlIHRvbyBtYW55IHJlY29yZHMuIEV2ZXJ5IHJlY29yZCBvYmplY3"
+             "QgaXMgOTYgYnl0ZXMgKyBoZWFwLiBJZiBhIHNtYWxsIHZhbHVlIHN0cmluZyBpcyB1c2VkIHBlciBvYmplY3QsIHdoZW4gd"
+             "GhpcyBqc29uIGlzIHBhcnNlZCwgdGhlIG1lbW9yeSByZXF1aXJlbWVudHMgYXJlIG11Y2ggbW9yZSB0aGFuIHRoZSByZXF1"
+             "ZXN0IGl0c2VsZi4gTWVzc2FnZSBFbmQuIE1lc3NhZ2UgU3RhcnQuIFVzaW5nIGEgbG9uZyBzZW50ZW5jZSB0byBiZSBhYmx"
+             "lIHRvIHJlYWNoIHRoZSBhdmFpbGFibGUgbWVtb3J5IGxpbWl0IHdpdGhvdXQgaGF2aW5nIHRvIHVzZSB0b28gbWFueSByZW"
+             "NvcmRzLiBFdmVyeSByZWNvcmQgb2JqZWN0IGlzIDk2IGJ5dGVzICsgaGVhcC4gSWYgYSBzbWFsbCB2YWx1ZSBzdHJpbmcga"
+             "XMgdXNlZCBwZXIgb2JqZWN0LCB3aGVuIHRoaXMganNvbiBpcyBwYXJzZWQsIHRoZSBtZW1vcnkgcmVxdWlyZW1lbnRzIGFy"
+             "ZSBtdWNoIG1vcmUgdGhhbiB0aGUgcmVxdWVzdCBpdHNlbGYuIE1lc3NhZ2UgRW5kLiBNZXNzYWdlIFN0YXJ0LiBVc2luZyB"
+             "hIGxvbmcgc2VudGVuY2UgdG8gYmUgYWJsZSB0byByZWFjaCB0aGUgYXZhaWxhYmxlIG1lbW9yeSBsaW1pdCB3aXRob3V0IG"
+             "hhdmluZyB0byB1c2UgdG9vIG1hbnkgcmVjb3Jkcy4gRXZlcnkgcmVjb3JkIG9iamVjdCBpcyA5NiBieXRlcyArIGhlYXAuI"
+             "ElmIGEgc21hbGwgdmFsdWUgc3RyaW5nIGlzIHVzZWQgcGVyIG9iamVjdCwgd2hlbiB0aGlzIGpzb24gaXMgcGFyc2VkLCB0"
+             "aGUgbWVtb3J5IHJlcXVpcmVtZW50cyBhcmUgbXVjaCBtb3JlIHRoYW4gdGhlIHJlcXVlc3QgaXRzZWxmLiBNZXNzYWdlIEV"
+             "uZC4gTWVzc2FnZSBTdGFydC4gVXNpbmcgYSBsb25nIHNlbnRlbmNlIHRvIGJlIGFibGUgdG8gcmVhY2ggdGhlIGF2YWlsYW"
+             "JsZSBtZW1vcnkgbGltaXQgd2l0aG91dCBoYXZpbmcgdG8gdXNlIHRvbyBtYW55IHJlY29yZHMuIEV2ZXJ5IHJlY29yZCBvY"
+             "mplY3QgaXMgOTYgYnl0ZXMgKyBoZWFwLiBJZiBhIHNtYWxsIHZhbHVlIHN0cmluZyBpcyB1c2VkIHBlciBvYmplY3QsIHdo"
+             "ZW4gdGhpcyBqc29uIGlzIHBhcnNlZCwgdGhlIG1lbW9yeSByZXF1aXJlbWVudHMgYXJlIG11Y2ggbW9yZSB0aGFuIHRoZSB"
+             "yZXF1ZXN0IGl0c2VsZi4gTWVzc2FnZSBFbmQuIE1lc3NhZ2UgU3RhcnQuIFVzaW5nIGEgbG9uZyBzZW50ZW5jZSB0byBiZS"
+             "BhYmxlIHRvIHJlYWNoIHRoZSBhdmFpbGFibGUgbWVtb3J5IGxpbWl0IHdpdGhvdXQgaGF2aW5nIHRvIHVzZSB0b28gbWFue"
+             "SByZWNvcmRzLiBFdmVyeSByZWNvcmQgb2JqZWN0IGlzIDk2IGJ5dGVzICsgaGVhcC4gSWYgYSBzbWFsbCB2YWx1ZSBzdHJp"
+             "bmcgaXMgdXNlZCBwZXIgb2JqZWN0LCB3aGVuIHRoaXMganNvbiBpcyBwYXJzZWQsIHRoZSBtZW1vcnkgcmVxdWlyZW1lbnR"
+             "zIGFyZSBtdWNoIG1vcmUgdGhhbiB0aGUgcmVxdWVzdCBpdHNlbGYuIE1lc3NhZ2UgRW5kLg=="
+             )
+        }
+        values = [value for _ in range(50000)]
+        data = {"records": values}
+        data_json = json.dumps(data)
+
+        # With 256Mb available per core, the available memory for the kafka services
+        # is 90.4Mb at most. We want to ensure that this request is larger than this
+        memory_limit = 90.4 * 1024 * 1024
+        assert len(data_json) > memory_limit, \
+            f"Expected request larger than {memory_limit}b. Got {len(data_json)}b, instead"
+
+        self.logger.info(f"Creating test topic: {name}")
+        self._create_topics([name], partitions=3)
+
+        self.logger.info(f"Producing to topic: {name}")
+        produce_result_raw = self._produce_topic(name, data_json)
+        assert produce_result_raw.status_code == PAYLOAD_TOO_LARGE_HTTP_ERROR_CODE, \
+                f"Expected '{PAYLOAD_TOO_LARGE_HTTP_ERROR_CODE}' " \
+                f"but got '{produce_result_raw.status_code}' instead"
+
 
 class PandaProxySASLTest(PandaProxyEndpoints):
     """