Change sender's viewer

14 files changed, 539 insertions, 46 deletions

diff --git a/ydb/core/cms/ui/datashard_info.js b/ydb/core/cms/ui/datashard_info.js
index f1c8bad40f..1c35b4cc7f 100644
--- a/ydb/core/cms/ui/datashard_info.js
+++ b/ydb/core/cms/ui/datashard_info.js
@@ -104,6 +104,7 @@ function onDataShardInfoLoaded(data) {
     $('#tablet-info-role').text(info.IsFollower ? 'Follower' : 'Leader');
     $('#tablet-info-state').text(info.State + (info.IsActive ? ' (active)' : ' (inactive)'));
     $('#tablet-info-shared-blobs').text(info.HasSharedBlobs);
+    $('#tablet-info-change-sender').html('<a href="app?TabletID=' + TabletId + '&page=change-sender">Viewer</a>');
 
     var activities = data.Activities;
     if (activities) {
diff --git a/ydb/core/tx/datashard/CMakeLists.darwin-x86_64.txt b/ydb/core/tx/datashard/CMakeLists.darwin-x86_64.txt
index 36883adf5d..4c48c4f6ce 100644
--- a/ydb/core/tx/datashard/CMakeLists.darwin-x86_64.txt
+++ b/ydb/core/tx/datashard/CMakeLists.darwin-x86_64.txt
@@ -113,6 +113,7 @@ target_link_libraries(core-tx-datashard PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
@@ -164,6 +165,7 @@ target_sources(core-tx-datashard PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_async_index.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_common_ops.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_monitoring.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_commit_writes_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_data_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_distributed_erase_tx_unit.cpp
@@ -370,6 +372,7 @@ target_link_libraries(core-tx-datashard.global PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
diff --git a/ydb/core/tx/datashard/CMakeLists.linux-aarch64.txt b/ydb/core/tx/datashard/CMakeLists.linux-aarch64.txt
index 5a350e0524..3715d25663 100644
--- a/ydb/core/tx/datashard/CMakeLists.linux-aarch64.txt
+++ b/ydb/core/tx/datashard/CMakeLists.linux-aarch64.txt
@@ -114,6 +114,7 @@ target_link_libraries(core-tx-datashard PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
@@ -165,6 +166,7 @@ target_sources(core-tx-datashard PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_async_index.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_common_ops.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_monitoring.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_commit_writes_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_data_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_distributed_erase_tx_unit.cpp
@@ -372,6 +374,7 @@ target_link_libraries(core-tx-datashard.global PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
diff --git a/ydb/core/tx/datashard/CMakeLists.linux-x86_64.txt b/ydb/core/tx/datashard/CMakeLists.linux-x86_64.txt
index 5a350e0524..3715d25663 100644
--- a/ydb/core/tx/datashard/CMakeLists.linux-x86_64.txt
+++ b/ydb/core/tx/datashard/CMakeLists.linux-x86_64.txt
@@ -114,6 +114,7 @@ target_link_libraries(core-tx-datashard PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
@@ -165,6 +166,7 @@ target_sources(core-tx-datashard PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_async_index.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_common_ops.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_monitoring.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_commit_writes_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_data_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_distributed_erase_tx_unit.cpp
@@ -372,6 +374,7 @@ target_link_libraries(core-tx-datashard.global PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
diff --git a/ydb/core/tx/datashard/CMakeLists.windows-x86_64.txt b/ydb/core/tx/datashard/CMakeLists.windows-x86_64.txt
index 960d938fb5..ec9dc257dd 100644
--- a/ydb/core/tx/datashard/CMakeLists.windows-x86_64.txt
+++ b/ydb/core/tx/datashard/CMakeLists.windows-x86_64.txt
@@ -114,6 +114,7 @@ target_link_libraries(core-tx-datashard PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
@@ -165,6 +166,7 @@ target_sources(core-tx-datashard PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_async_index.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_common_ops.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/change_sender_monitoring.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_commit_writes_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_data_tx_unit.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/datashard/check_distributed_erase_tx_unit.cpp
@@ -367,6 +369,7 @@ target_link_libraries(core-tx-datashard.global PUBLIC
   cpp-html-pcdata
   library-cpp-json
   cpp-json-yson
+  monlib-service-pages
   cpp-string_utils-base64
   cpp-string_utils-quote
   ydb-core-actorlib_impl
diff --git a/ydb/core/tx/datashard/change_sender.cpp b/ydb/core/tx/datashard/change_sender.cpp
index fa3193c743..48ab790c6c 100644
--- a/ydb/core/tx/datashard/change_sender.cpp
+++ b/ydb/core/tx/datashard/change_sender.cpp
@@ -1,5 +1,6 @@
 #include "change_exchange.h"
 #include "change_exchange_impl.h"
+#include "change_sender_monitoring.h"
 #include "datashard_impl.h"
 
 #include <ydb/core/protos/services.pb.h>
@@ -7,12 +8,14 @@
 #include <library/cpp/actors/core/actor.h>
 #include <library/cpp/actors/core/hfunc.h>
 #include <library/cpp/actors/core/log.h>
+#include <library/cpp/actors/core/mon.h>
+#include <library/cpp/monlib/service/pages/mon_page.h>
+#include <library/cpp/monlib/service/pages/templates.h>
 
 #include <util/generic/hash.h>
 #include <util/generic/maybe.h>
 
-namespace NKikimr {
-namespace NDataShard {
+namespace NKikimr::NDataShard {
 
 class TChangeSender: public TActor<TChangeSender> {
     using ESenderType = TEvChangeExchange::ESenderType;
@@ -161,6 +164,91 @@ class TChangeSender: public TActor<TChangeSender> {
         }
     }
 
+    void Handle(NMon::TEvRemoteHttpInfo::TPtr& ev, const TActorContext& ctx) {
+        const auto& cgi = ev->Get()->Cgi();
+        if (const auto& str = cgi.Get("pathId")) {
+            if (const auto& pathId = ParsePathId(str)) {
+                auto it = Senders.find(pathId);
+                if (it != Senders.end()) {
+                    if (const auto& to = it->second.ActorId) {
+                        ctx.Send(ev->Forward(to));
+                    } else {
+                        Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(TStringBuilder()
+                            << "Change sender '" << pathId << "' (" << it->second.Type << ") is not running"));
+                    }
+                } else {
+                    Send(ev->Sender, new NMon::TEvRemoteBinaryInfoRes(NMonitoring::HTTPNOTFOUND));
+                }
+            } else {
+                Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes("Invalid pathId"));
+            }
+
+            return;
+        }
+
+        TStringStream html;
+
+        HTML(html) {
+            Header(html, "Main change sender", DataShard.TabletId);
+
+            SimplePanel(html, "Senders", [this](IOutputStream& html) {
+                HTML(html) {
+                    TABLE_CLASS("table table-hover") {
+                        TABLEHEAD() {
+                            TABLER() {
+                                TABLEH() { html << "#"; }
+                                TABLEH() { html << "PathId"; }
+                                TABLEH() { html << "UserTableId"; }
+                                TABLEH() { html << "Type"; }
+                                TABLEH() { html << "Actor"; }
+                            }
+                        }
+                        TABLEBODY() {
+                            ui32 i = 0;
+                            for (const auto& [pathId, sender] : Senders) {
+                                TABLER() {
+                                    TABLED() { html << ++i; }
+                                    TABLED() { PathLink(html, pathId); }
+                                    TABLED() { html << sender.UserTableId; }
+                                    TABLED() { html << sender.Type; }
+                                    TABLED() { ActorLink(html, DataShard.TabletId, pathId); }
+                                }
+                            }
+                        }
+                    }
+                }
+            });
+
+            CollapsedPanel(html, "Enqueued", "enqueued", [this](IOutputStream& html) {
+                HTML(html) {
+                    TABLE_CLASS("table table-hover") {
+                        TABLEHEAD() {
+                            TABLER() {
+                                TABLEH() { html << "#"; }
+                                TABLEH() { html << "Order"; }
+                                TABLEH() { html << "PathId"; }
+                                TABLEH() { html << "BodySize"; }
+                            }
+                        }
+                        TABLEBODY() {
+                            ui32 i = 0;
+                            for (const auto& record : Enqueued) {
+                                TABLER() {
+                                    TABLED() { html << ++i; }
+                                    TABLED() { html << record.Order; }
+                                    TABLED() { PathLink(html, record.PathId); }
+                                    TABLED() { html << record.BodySize; }
+                                }
+                            }
+                        }
+                    }
+                }
+            });
+        }
+
+        Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(html.Str()));
+    }
+
     void PassAway() override {
         for (const auto& [_, sender] : Senders) {
             if (!sender.ActorId) {
@@ -199,26 +287,26 @@ public:
         }
     }
 
-    STATEFN(StateBase) {
+    STFUNC(StateBase) {
         switch (ev->GetTypeRewrite()) {
             hFunc(TEvChangeExchange::TEvEnqueueRecords, Handle);
             hFunc(TEvChangeExchange::TEvAddSender, Handle);
             hFunc(TEvChangeExchange::TEvRemoveSender, Handle);
-
-            cFunc(TEvents::TEvPoison::EventType, PassAway);
+            HFunc(NMon::TEvRemoteHttpInfo, Handle);
+            sFunc(TEvents::TEvPoison, PassAway);
         }
     }
 
-    STATEFN(StateInactive) {
+    STFUNC(StateInactive) {
         switch (ev->GetTypeRewrite()) {
             hFunc(TEvChangeExchange::TEvActivateSender, Handle);
         default:
-            return StateBase(ev, TlsActivationContext->AsActorContext());
+            return StateBase(ev, ctx);
         }
     }
 
-    STATEFN(StateActive) {
-        return StateBase(ev, TlsActivationContext->AsActorContext());
+    STFUNC(StateActive) {
+        return StateBase(ev, ctx);
     }
 
 private:
@@ -234,5 +322,4 @@ IActor* CreateChangeSender(const TDataShard* self) {
     return new TChangeSender(self);
 }
 
-} // NDataShard
-} // NKikimr
+}
diff --git a/ydb/core/tx/datashard/change_sender_async_index.cpp b/ydb/core/tx/datashard/change_sender_async_index.cpp
index 554f4a9f81..34b40d876b 100644
--- a/ydb/core/tx/datashard/change_sender_async_index.cpp
+++ b/ydb/core/tx/datashard/change_sender_async_index.cpp
@@ -1,24 +1,24 @@
 #include "change_exchange.h"
 #include "change_exchange_impl.h"
 #include "change_sender_common_ops.h"
+#include "change_sender_monitoring.h"
 
 #include <ydb/core/base/tablet_pipecache.h>
 #include <ydb/core/protos/services.pb.h>
 #include <ydb/core/tablet_flat/flat_row_eggs.h>
 #include <ydb/core/tx/tx_proxy/proxy.h>
+#include <ydb/library/yql/public/udf/udf_data_type.h>
 
 #include <library/cpp/actors/core/actor_bootstrapped.h>
 #include <library/cpp/actors/core/hfunc.h>
 #include <library/cpp/actors/core/log.h>
 
-#include <ydb/library/yql/public/udf/udf_data_type.h>
-
 #include <util/generic/maybe.h>
 
-namespace NKikimr {
-namespace NDataShard {
+namespace NKikimr::NDataShard {
 
 using namespace NTable;
+using ESenderType = TEvChangeExchange::ESenderType;
 
 class TAsyncIndexChangeSenderShard: public TActorBootstrapped<TAsyncIndexChangeSenderShard> {
     TStringBuf GetLogPrefix() const {
@@ -196,6 +196,27 @@ class TAsyncIndexChangeSenderShard: public TActorBootstrapped<TAsyncIndexChangeS
         Leave();
     }
 
+    void Handle(NMon::TEvRemoteHttpInfo::TPtr& ev) {
+        TStringStream html;
+
+        HTML(html) {
+            Header(html, "AsyncIndex partition change sender", DataShard.TabletId);
+
+            SimplePanel(html, "Info", [this](IOutputStream& html) {
+                HTML(html) {
+                    DL_CLASS("dl-horizontal") {
+                        TermDesc(html, "ShardId", ShardId);
+                        TermDesc(html, "IndexTablePathId", IndexTablePathId);
+                        TermDesc(html, "LeaderPipeCache", LeaderPipeCache);
+                        TermDesc(html, "LastRecordOrder", LastRecordOrder);
+                    }
+                }
+            });
+        }
+
+        Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(html.Str()));
+    }
+
     void Leave() {
         Send(Parent, new TEvChangeExchangePrivate::TEvGone(ShardId));
         PassAway();
@@ -232,6 +253,7 @@ public:
     STATEFN(StateBase) {
         switch (ev->GetTypeRewrite()) {
             hFunc(TEvPipeCache::TEvDeliveryProblem, Handle);
+            hFunc(NMon::TEvRemoteHttpInfo, Handle);
             sFunc(TEvents::TEvPoison, PassAway);
         }
     }
@@ -249,11 +271,12 @@ private:
 
 }; // TAsyncIndexChangeSenderShard
 
-class TAsyncIndexChangeSenderMain: public TActorBootstrapped<TAsyncIndexChangeSenderMain>
-                                 , public TBaseChangeSender
-                                 , public IChangeSenderResolver
-                                 , private TSchemeCacheHelpers {
-
+class TAsyncIndexChangeSenderMain
+    : public TActorBootstrapped<TAsyncIndexChangeSenderMain>
+    , public TBaseChangeSender
+    , public IChangeSenderResolver
+    , private TSchemeCacheHelpers
+{
     TStringBuf GetLogPrefix() const {
         if (!LogPrefix) {
             LogPrefix = TStringBuilder()
@@ -682,6 +705,10 @@ class TAsyncIndexChangeSenderMain: public TActorBootstrapped<TAsyncIndexChangeSe
         PassAway();
     }
 
+    void Handle(NMon::TEvRemoteHttpInfo::TPtr& ev, const TActorContext& ctx) {
+        RenderHtmlPage(ESenderType::AsyncIndex, ev, ctx);
+    }
+
     void PassAway() override {
         KillSenders();
         TActorBootstrapped::PassAway();
@@ -703,7 +730,7 @@ public:
         ResolveUserTable();
     }
 
-    STATEFN(StateBase) {
+    STFUNC(StateBase) {
         switch (ev->GetTypeRewrite()) {
             hFunc(TEvChangeExchange::TEvEnqueueRecords, Handle);
             hFunc(TEvChangeExchange::TEvRecords, Handle);
@@ -711,6 +738,7 @@ public:
             hFunc(TEvChangeExchange::TEvRemoveSender, Handle);
             hFunc(TEvChangeExchangePrivate::TEvReady, Handle);
             hFunc(TEvChangeExchangePrivate::TEvGone, Handle);
+            HFunc(NMon::TEvRemoteHttpInfo, Handle);
             sFunc(TEvents::TEvPoison, PassAway);
         }
     }
@@ -731,5 +759,4 @@ IActor* CreateAsyncIndexChangeSender(const TDataShardId& dataShard, const TTable
     return new TAsyncIndexChangeSenderMain(dataShard, userTableId, indexPathId);
 }
 
-} // NDataShard
-} // NKikimr
+}
diff --git a/ydb/core/tx/datashard/change_sender_cdc_stream.cpp b/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
index 5c79897e55..533b001e8d 100644
--- a/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
+++ b/ydb/core/tx/datashard/change_sender_cdc_stream.cpp
@@ -1,23 +1,24 @@
 #include "change_exchange.h"
 #include "change_exchange_impl.h"
 #include "change_sender_common_ops.h"
+#include "change_sender_monitoring.h"
 #include "datashard_user_table.h"
 
-#include <library/cpp/actors/core/actor_bootstrapped.h>
-#include <library/cpp/actors/core/hfunc.h>
-#include <library/cpp/actors/core/log.h>
-#include <library/cpp/json/json_writer.h>
-
 #include <ydb/core/persqueue/partition_key_range/partition_key_range.h>
 #include <ydb/core/persqueue/writer/source_id_encoding.h>
 #include <ydb/core/persqueue/writer/writer.h>
 #include <ydb/core/protos/grpc_pq_old.pb.h>
 #include <ydb/services/lib/sharding/sharding.h>
 
-namespace NKikimr {
-namespace NDataShard {
+#include <library/cpp/actors/core/actor_bootstrapped.h>
+#include <library/cpp/actors/core/hfunc.h>
+#include <library/cpp/actors/core/log.h>
+#include <library/cpp/json/json_writer.h>
+
+namespace NKikimr::NDataShard {
 
 using namespace NPQ;
+using ESenderType = TEvChangeExchange::ESenderType;
 
 class TCdcChangeSenderPartition: public TActorBootstrapped<TCdcChangeSenderPartition> {
     TStringBuf GetLogPrefix() const {
@@ -165,7 +166,7 @@ class TCdcChangeSenderPartition: public TActorBootstrapped<TCdcChangeSenderParti
 
         const auto& result = *ev->Get();
         if (!result.IsSuccess()) {
-            LOG_E("Error at 'Write"
+            LOG_E("Error at 'Write'"
                 << ": reason# " << result.GetError().Reason);
             return Leave();
         }
@@ -203,6 +204,30 @@ class TCdcChangeSenderPartition: public TActorBootstrapped<TCdcChangeSenderParti
         Ready();
     }
 
+    void Handle(NMon::TEvRemoteHttpInfo::TPtr& ev) {
+        TStringStream html;
+
+        HTML(html) {
+            Header(html, "CdcStream partition change sender", DataShard.TabletId);
+
+            SimplePanel(html, "Info", [this](IOutputStream& html) {
+                HTML(html) {
+                    DL_CLASS("dl-horizontal") {
+                        TermDesc(html, "PartitionId", PartitionId);
+                        TermDesc(html, "ShardId", ShardId);
+                        TermDesc(html, "SourceId", SourceId);
+                        TermDesc(html, "Writer", Writer);
+                        TermDesc(html, "MaxSeqNo", MaxSeqNo);
+                        TermDesc(html, "Pending", Pending.size());
+                        TermDesc(html, "Cookie", Cookie);
+                    }
+                }
+            });
+        }
+
+        Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(html.Str()));
+    }
+
     void Leave() {
         Send(Parent, new TEvChangeExchangePrivate::TEvGone(PartitionId));
         PassAway();
@@ -247,6 +272,7 @@ public:
     STATEFN(StateBase) {
         switch (ev->GetTypeRewrite()) {
             sFunc(TEvPartitionWriter::TEvDisconnected, Leave);
+            hFunc(NMon::TEvRemoteHttpInfo, Handle);
             sFunc(TEvents::TEvPoison, PassAway);
         }
     }
@@ -267,11 +293,12 @@ private:
 
 }; // TCdcChangeSenderPartition
 
-class TCdcChangeSenderMain: public TActorBootstrapped<TCdcChangeSenderMain>
-                          , public TBaseChangeSender
-                          , public IChangeSenderResolver
-                          , private TSchemeCacheHelpers {
-
+class TCdcChangeSenderMain
+    : public TActorBootstrapped<TCdcChangeSenderMain>
+    , public TBaseChangeSender
+    , public IChangeSenderResolver
+    , private TSchemeCacheHelpers
+{
     struct TPQPartitionInfo {
         ui32 PartitionId;
         ui64 ShardId;
@@ -699,6 +726,10 @@ class TCdcChangeSenderMain: public TActorBootstrapped<TCdcChangeSenderMain>
         PassAway();
     }
 
+    void Handle(NMon::TEvRemoteHttpInfo::TPtr& ev, const TActorContext& ctx) {
+        RenderHtmlPage(ESenderType::CdcStream, ev, ctx);
+    }
+
     void PassAway() override {
         KillSenders();
         TActorBootstrapped::PassAway();
@@ -719,7 +750,7 @@ public:
         ResolveCdcStream();
     }
 
-    STATEFN(StateBase) {
+    STFUNC(StateBase) {
         switch (ev->GetTypeRewrite()) {
             hFunc(TEvChangeExchange::TEvEnqueueRecords, Handle);
             hFunc(TEvChangeExchange::TEvRecords, Handle);
@@ -727,6 +758,7 @@ public:
             hFunc(TEvChangeExchange::TEvRemoveSender, Handle);
             hFunc(TEvChangeExchangePrivate::TEvReady, Handle);
             hFunc(TEvChangeExchangePrivate::TEvGone, Handle);
+            HFunc(NMon::TEvRemoteHttpInfo, Handle);
             sFunc(TEvents::TEvPoison, PassAway);
         }
     }
@@ -745,5 +777,4 @@ IActor* CreateCdcStreamChangeSender(const TDataShardId& dataShard, const TPathId
     return new TCdcChangeSenderMain(dataShard, streamPathId);
 }
 
-} // NDataShard
-} // NKikimr
+}
diff --git a/ydb/core/tx/datashard/change_sender_common_ops.cpp b/ydb/core/tx/datashard/change_sender_common_ops.cpp
index 026c4033f2..201fd1c0a7 100644
--- a/ydb/core/tx/datashard/change_sender_common_ops.cpp
+++ b/ydb/core/tx/datashard/change_sender_common_ops.cpp
@@ -1,9 +1,12 @@
 #include "change_sender_common_ops.h"
+#include "change_sender_monitoring.h"
+
+#include <library/cpp/monlib/service/pages/mon_page.h>
+#include <library/cpp/monlib/service/pages/templates.h>
 
 #include <util/generic/size_literals.h>
 
-namespace NKikimr {
-namespace NDataShard {
+namespace NKikimr::NDataShard {
 
 void TBaseChangeSender::CreateSenders(const TVector<ui64>& partitionIds) {
     THashMap<ui64, TSender> senders;
@@ -254,5 +257,154 @@ TBaseChangeSender::TBaseChangeSender(IActorOps* actorOps, IChangeSenderResolver*
 {
 }
 
-} // NDataShard
-} // NKikimr
+void TBaseChangeSender::RenderHtmlPage(TEvChangeExchange::ESenderType type, NMon::TEvRemoteHttpInfo::TPtr& ev,
+        const TActorContext& ctx)
+{
+    const auto& cgi = ev->Get()->Cgi();
+    if (const auto& str = cgi.Get("partitionId")) {
+        ui64 partitionId = 0;
+        if (TryFromString(str, partitionId)) {
+            auto it = Senders.find(partitionId);
+            if (it != Senders.end()) {
+                if (const auto& to = it->second.ActorId) {
+                    ctx.Send(ev->Forward(to));
+                } else {
+                    ActorOps->Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(TStringBuilder()
+                        << "Change sender '" << PathId << ":" << partitionId << "' is not running"));
+                }
+            } else {
+                ActorOps->Send(ev->Sender, new NMon::TEvRemoteBinaryInfoRes(NMonitoring::HTTPNOTFOUND));
+            }
+        } else {
+            ActorOps->Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes("Invalid partitionId"));
+        }
+
+        return;
+    }
+
+    TStringStream html;
+
+    HTML(html) {
+        Header(html, TStringBuilder() << type << " change sender", DataShard.TabletId);
+
+        SimplePanel(html, "Partition senders", [this](IOutputStream& html) {
+            HTML(html) {
+                TABLE_CLASS("table table-hover") {
+                    TABLEHEAD() {
+                        TABLER() {
+                            TABLEH() { html << "#"; }
+                            TABLEH() { html << "PartitionId"; }
+                            TABLEH() { html << "Ready"; }
+                            TABLEH() { html << "Pending"; }
+                            TABLEH() { html << "Actor"; }
+                        }
+                    }
+                    TABLEBODY() {
+                        ui32 i = 0;
+                        for (const auto& [partitionId, sender] : Senders) {
+                            TABLER() {
+                                TABLED() { html << ++i; }
+                                TABLED() { html << partitionId; }
+                                TABLED() { html << sender.Ready; }
+                                TABLED() { html << sender.Pending.size(); }
+                                TABLED() { ActorLink(html, DataShard.TabletId, PathId, partitionId); }
+                            }
+                        }
+                    }
+                }
+            }
+        });
+
+        CollapsedPanel(html, "Enqueued", "enqueued", [this](IOutputStream& html) {
+            HTML(html) {
+                TABLE_CLASS("table table-hover") {
+                    TABLEHEAD() {
+                        TABLER() {
+                            TABLEH() { html << "#"; }
+                            TABLEH() { html << "Order"; }
+                            TABLEH() { html << "BodySize"; }
+                        }
+                    }
+                    TABLEBODY() {
+                        ui32 i = 0;
+                        for (const auto& record : Enqueued) {
+                            TABLER() {
+                                TABLED() { html << ++i; }
+                                TABLED() { html << record.Order; }
+                                TABLED() { html << record.BodySize; }
+                            }
+                        }
+                    }
+                }
+            }
+        });
+
+        CollapsedPanel(html, "PendingBody", "pendingBody", [this](IOutputStream& html) {
+            HTML(html) {
+                TABLE_CLASS("table table-hover") {
+                    TABLEHEAD() {
+                        TABLER() {
+                            TABLEH() { html << "#"; }
+                            TABLEH() { html << "Order"; }
+                            TABLEH() { html << "BodySize"; }
+                        }
+                    }
+                    TABLEBODY() {
+                        ui32 i = 0;
+                        for (const auto& record : PendingBody) {
+                            TABLER() {
+                                TABLED() { html << ++i; }
+                                TABLED() { html << record.Order; }
+                                TABLED() { html << record.BodySize; }
+                            }
+                        }
+                    }
+                }
+            }
+        });
+
+        CollapsedPanel(html, "PendingSent", "pendingSent", [this](IOutputStream& html) {
+            HTML(html) {
+                TABLE_CLASS("table table-hover") {
+                    TABLEHEAD() {
+                        TABLER() {
+                            TABLEH() { html << "#"; }
+                            TABLEH() { html << "Order"; }
+                            TABLEH() { html << "Group"; }
+                            TABLEH() { html << "Step"; }
+                            TABLEH() { html << "TxId"; }
+                            TABLEH() { html << "LockId"; }
+                            TABLEH() { html << "LockOffset"; }
+                            TABLEH() { html << "PathId"; }
+                            TABLEH() { html << "Kind"; }
+                            TABLEH() { html << "TableId"; }
+                            TABLEH() { html << "SchemaVersion"; }
+                        }
+                    }
+                    TABLEBODY() {
+                        ui32 i = 0;
+                        for (const auto& [order, record] : PendingSent) {
+                            TABLER() {
+                                TABLED() { html << ++i; }
+                                TABLED() { html << order; }
+                                TABLED() { html << record.GetGroup(); }
+                                TABLED() { html << record.GetStep(); }
+                                TABLED() { html << record.GetTxId(); }
+                                TABLED() { html << record.GetLockId(); }
+                                TABLED() { html << record.GetLockOffset(); }
+                                TABLED() { PathLink(html, record.GetPathId()); }
+                                TABLED() { html << record.GetKind(); }
+                                TABLED() { PathLink(html, record.GetTableId()); }
+                                TABLED() { html << record.GetSchemaVersion(); }
+                            }
+                        }
+                    }
+                }
+            }
+        });
+    }
+
+    ActorOps->Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes(html.Str()));
+}
+
+}
diff --git a/ydb/core/tx/datashard/change_sender_common_ops.h b/ydb/core/tx/datashard/change_sender_common_ops.h
index efff4a722e..ce58902538 100644
--- a/ydb/core/tx/datashard/change_sender_common_ops.h
+++ b/ydb/core/tx/datashard/change_sender_common_ops.h
@@ -8,6 +8,7 @@
 
 #include <library/cpp/actors/core/actor.h>
 #include <library/cpp/actors/core/hfunc.h>
+#include <library/cpp/actors/core/mon.h>
 
 #include <util/generic/hash.h>
 #include <util/generic/map.h>
@@ -105,6 +106,8 @@ protected:
     explicit TBaseChangeSender(IActorOps* actorOps, IChangeSenderResolver* resolver,
         const TDataShardId& dataShard, const TPathId& pathId);
 
+    void RenderHtmlPage(TEvChangeExchange::ESenderType type, NMon::TEvRemoteHttpInfo::TPtr& ev, const TActorContext& ctx);
+
 private:
     IActorOps* const ActorOps;
     IChangeSenderResolver* const Resolver;
diff --git a/ydb/core/tx/datashard/change_sender_monitoring.cpp b/ydb/core/tx/datashard/change_sender_monitoring.cpp
new file mode 100644
index 0000000000..d6d311b7aa
--- /dev/null
+++ b/ydb/core/tx/datashard/change_sender_monitoring.cpp
@@ -0,0 +1,116 @@
+#include "change_sender_monitoring.h"
+
+#include <util/string/cast.h>
+#include <util/string/split.h>
+
+namespace NKikimr::NDataShard {
+
+void Panel(IOutputStream& str, std::function<void(IOutputStream&)> title, std::function<void(IOutputStream&)> body) {
+    HTML(str) {
+        DIV_CLASS("panel panel-default") {
+            DIV_CLASS("panel-heading") {
+                H4_CLASS("panel-title") {
+                    title(str);
+                }
+            }
+            body(str);
+        }
+    }
+}
+
+void SimplePanel(IOutputStream& str, const TStringBuf title, std::function<void(IOutputStream&)> body) {
+    auto titleRenderer = [&title](IOutputStream& str) {
+        HTML(str) {
+            str << title;
+        }
+    };
+
+    auto bodyRenderer = [body = std::move(body)](IOutputStream& str) {
+        HTML(str) {
+            DIV_CLASS("panel-body") {
+                body(str);
+            }
+        }
+    };
+
+    Panel(str, std::move(titleRenderer), std::move(bodyRenderer));
+}
+
+void CollapsedPanel(IOutputStream& str, const TStringBuf title, const TStringBuf targetId,
+        std::function<void(IOutputStream&)> body)
+{
+    auto titleRenderer = [&title, &targetId](IOutputStream& str) {
+        HTML(str) {
+            str << "<a data-toggle='collapse' href='#" << targetId << "'>"
+                << title
+            << "</a>";
+        }
+    };
+
+    auto bodyRenderer = [&targetId, body = std::move(body)](IOutputStream& str) {
+        HTML(str) {
+            str << "<div id='" << targetId << "' class='collapse'>";
+            DIV_CLASS("panel-body") {
+                body(str);
+            }
+            str << "</div>";
+        }
+    };
+
+    Panel(str, std::move(titleRenderer), std::move(bodyRenderer));
+}
+
+template <typename P, typename D>
+static bool TryGetNext(TStringBuf& s, D delim, P& param) {
+    TMaybe<TStringBuf> buf;
+    GetNext(s, delim, buf);
+    if (!buf) {
+        return false;
+    }
+
+    return TryFromString(*buf, param);
+}
+
+TPathId ParsePathId(TStringBuf str) {
+    ui64 ownerId;
+    ui64 localPathId;
+
+    if (!TryGetNext(str, ':', ownerId) || !TryGetNext(str, ':', localPathId)) {
+        return {};
+    }
+
+    return TPathId(ownerId, localPathId);
+}
+
+template <typename T>
+static void Link(IOutputStream& str, const TStringBuf path, const T& title) {
+    HTML(str) {
+        HREF(path) {
+            str << title;
+        }
+    }
+}
+
+void PathLink(IOutputStream& str, const TPathId& pathId) {
+    const TString path = TStringBuilder() << "app"
+        << "?TabletID=" << pathId.OwnerId
+        << "&Page=" << "PathInfo"
+        << "&OwnerPathId=" << pathId.OwnerId
+        << "&LocalPathId=" << pathId.LocalPathId;
+    Link(str, path, pathId);
+}
+
+void ActorLink(IOutputStream& str, ui64 tabletId, const TPathId& pathId, const TMaybe<ui64>& partitionId) {
+    auto path = TStringBuilder() << "app"
+        << "?TabletID=" << tabletId
+        << "&page=" << "change-sender"
+        << "&pathId=" << pathId.OwnerId << ":" << pathId.LocalPathId;
+
+    if (partitionId) {
+        path << "&partitionId=" << partitionId;
+    }
+
+    Link(str, path, "Viewer");
+}
+
+}
diff --git a/ydb/core/tx/datashard/change_sender_monitoring.h b/ydb/core/tx/datashard/change_sender_monitoring.h
new file mode 100644
index 0000000000..14d901e251
--- /dev/null
+++ b/ydb/core/tx/datashard/change_sender_monitoring.h
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <ydb/core/base/pathid.h>
+
+#include <library/cpp/monlib/service/pages/templates.h>
+
+#include <util/string/printf.h>
+
+namespace NKikimr::NDataShard {
+
+template <typename T>
+void Header(IOutputStream& str, const T& title, ui64 tabletId) {
+    HTML(str) {
+        DIV_CLASS("page-header") {
+            TAG(TH3) {
+                str << title;
+                SMALL() {
+                    str << "&nbsp;";
+                    HREF(Sprintf("app?TabletID=%" PRIu64, tabletId)) {
+                        str << tabletId;
+                    }
+                }
+            }
+        }
+    }
+}
+
+template <typename T>
+static void TermDesc(IOutputStream& str, const TStringBuf term, const T& desc) {
+    HTML(str) {
+        DT() { str << term; }
+        DD() { str << desc; }
+    }
+}
+
+void Panel(IOutputStream& str, std::function<void(IOutputStream&)> title, std::function<void(IOutputStream&)> body);
+void SimplePanel(IOutputStream& str, const TStringBuf title, std::function<void(IOutputStream&)> body);
+void CollapsedPanel(IOutputStream& str, const TStringBuf title, const TStringBuf targetId,
+    std::function<void(IOutputStream&)> body);
+
+TPathId ParsePathId(TStringBuf str);
+void PathLink(IOutputStream& str, const TPathId& pathId);
+void ActorLink(IOutputStream& str, ui64 tabletId, const TPathId& pathId, const TMaybe<ui64>& partitionId = {});
+
+}
diff --git a/ydb/core/tx/datashard/datashard.cpp b/ydb/core/tx/datashard/datashard.cpp
index e96eaff9d9..a40d95de94 100644
--- a/ydb/core/tx/datashard/datashard.cpp
+++ b/ydb/core/tx/datashard/datashard.cpp
@@ -1809,8 +1809,7 @@ bool TDataShard::OnRenderAppHtmlPage(NMon::TEvRemoteHttpInfo::TPtr ev, const TAc
 
     auto cgi = ev->Get()->Cgi();
 
-    auto action = cgi.Get("action");
-    if (action) {
+    if (const auto& action = cgi.Get("action")) {
         if (action == "cleanup-borrowed-parts") {
             Execute(CreateTxMonitoringCleanupBorrowedParts(this, ev), ctx);
             return true;
@@ -1832,8 +1831,24 @@ bool TDataShard::OnRenderAppHtmlPage(NMon::TEvRemoteHttpInfo::TPtr ev, const TAc
         return true;
     }
 
-    Execute(CreateTxMonitoring(this, ev), ctx);
+    if (const auto& page = cgi.Get("page")) {
+        if (page == "main") {
+            // fallthrough
+        } else if (page == "change-sender") {
+            if (OutChangeSender) {
+                ctx.Send(ev->Forward(OutChangeSender));
+                return true;
+            } else {
+                ctx.Send(ev->Sender, new NMon::TEvRemoteHttpInfoRes("Change sender is not running"));
+                return true;
+            }
+        } else {
+            ctx.Send(ev->Sender, new NMon::TEvRemoteBinaryInfoRes(NMonitoring::HTTPNOTFOUND));
+            return true;
+        }
+    }
 
+    Execute(CreateTxMonitoring(this, ev), ctx);
     return true;
 }
 
diff --git a/ydb/core/tx/datashard/index.html b/ydb/core/tx/datashard/index.html
index 776f3a97a3..dd4ac646da 100644
--- a/ydb/core/tx/datashard/index.html
+++ b/ydb/core/tx/datashard/index.html
@@ -89,6 +89,10 @@
                     <td class="ds-info">HasSharedBlobs</td>
                     <td class="ds-info" id="tablet-info-shared-blobs">Loading...</td>
                   </tr>
+                  <tr class="ds-info">
+                    <td class="ds-info">Change sender</td>
+                    <td class="ds-info" id="tablet-info-change-sender">Loading...</td>
+                  </tr>
                 </tbody>
               </table>
               <table class="ds-info">