Pizdec

2026-10-03 22:09:58 +03:00
commit 8d4b15dbcf
33 changed files with 1655 additions and 0 deletions
@@ -0,0 +1,3 @@
+/gradlew text eol=lf
+*.bat text eol=crlf
+*.jar binary
@@ -0,0 +1,37 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
@@ -0,0 +1,9 @@
+FROM eclipse-temurin:21-jre-alpine
+
+WORKDIR /app
+
+COPY build/libs/*.jar app.jar
+
+EXPOSE 8080
+
+ENTRYPOINT ["java", "-Djava.net.preferIPv4Stack=true", "-jar", "app.jar"]
@@ -0,0 +1,316 @@
+# Гайд по метрикам и мониторингу
+
+## Быстрый старт
+
+1. **Доступ к сервисам:**
+   - Приложение: http://localhost:8080
+   - Prometheus: http://localhost:9090
+   - Grafana: http://localhost:3000 (admin/admin)
+
+2. **Дашборды автоматически загружены:**
+   - Spring Boot Application Metrics
+   - PostgreSQL & HikariCP Monitoring
+
+## Основные метрики
+
+### HTTP метрики
+
+**Что смотреть:**
+- `http_server_requests_seconds_count` — количество запросов
+- `http_server_requests_seconds_sum` — суммарное время выполнения
+- `http_server_requests_seconds_bucket` — распределение времени ответа
+
+**Зачем:**
+- Отслеживать нагрузку на эндпоинты
+- Находить медленные запросы (p95, p99)
+- Видеть ошибки по статус-кодам
+
+**Пример запроса в Prometheus:**
+```promql
+# Request rate по эндпоинтам
+rate(http_server_requests_seconds_count{application="todo"}[1m])
+
+# 95-й перцентиль времени ответа
+histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket[5m])) by (le, uri))
+
+# Количество ошибок 5xx
+sum(rate(http_server_requests_seconds_count{status=~"5.."}[1m]))
+```
+
+### JVM метрики
+
+**Что смотреть:**
+- `jvm_memory_used_bytes` — используемая память (heap/non-heap)
+- `jvm_memory_max_bytes` — максимальная доступная память
+- `jvm_gc_pause_seconds` — время на GC паузах
+- `jvm_threads_live_threads` — количество потоков
+
+**Зачем:**
+- Проверить утечки памяти (постоянный рост heap)
+- Оптимизировать GC (частые паузы = проблема)
+- Контролировать создание потоков
+
+**Алерты:**
+```promql
+# Память heap больше 80%
+(jvm_memory_used_bytes{area="heap"} / jvm_memory_max_bytes{area="heap"}) > 0.8
+
+# GC паузы больше 100ms
+rate(jvm_gc_pause_seconds_sum[1m]) > 0.1
+```
+
+### Database Connection Pool (HikariCP)
+
+**Что смотреть:**
+- `hikaricp_connections_active` — активные соединения
+- `hikaricp_connections_idle` — простаивающие соединения
+- `hikaricp_connections_pending` — ожидающие потоки
+- `hikaricp_connections_timeout_total` — таймауты соединений
+- `hikaricp_connections_acquire_seconds` — время получения соединения
+
+**Зачем:**
+- Настроить размер пула (если active = max постоянно, увеличить)
+- Найти медленные запросы (высокое usage time)
+- Обнаружить connection leaks (timeouts растут)
+
+**Оптимальные значения:**
+- Active connections < 70% от max
+- Acquire time < 10ms (p95)
+- Pending threads = 0
+- Timeouts = 0
+
+**Алерты:**
+```promql
+# Пул заполнен больше 80%
+(hikaricp_connections_active / hikaricp_connections_max) > 0.8
+
+# Таймауты соединений
+rate(hikaricp_connections_timeout_total[1m]) > 0
+
+# Медленное получение соединений (p95 > 50ms)
+histogram_quantile(0.95, rate(hikaricp_connections_acquire_seconds_bucket[1m])) > 0.05
+```
+
+### System метрики
+
+**Что смотреть:**
+- `system_cpu_usage` — CPU системы
+- `process_cpu_usage` — CPU процесса
+- `disk_free_bytes` — свободное место на диске
+
+**Зачем:**
+- Контролировать нагрузку на CPU
+- Предотвратить переполнение диска
+
+## Использование Grafana
+
+### Навигация по дашбордам
+
+1. **Spring Boot Application Metrics:**
+   - HTTP Request Rate — количество запросов в секунду по эндпоинтам
+   - HTTP Request Duration — время ответа (p95, p99)
+   - HTTP Status Codes — распределение статус-кодов
+   - JVM Memory — использование heap/non-heap памяти
+   - Database Connection Pool — состояние пула соединений
+   - JVM Threads — количество потоков
+   - GC Pause Time — время на сборку мусора
+   - System CPU Usage — нагрузка на CPU
+
+2. **PostgreSQL & HikariCP Monitoring:**
+   - Connection Pool Status — статистика пула (active, idle, total, pending)
+   - Connection Pool Utilization — процент использования пула
+   - Connection Acquire Time — время получения соединения (перцентили)
+   - Connection Timeout Count — количество таймаутов
+   - Connection Creation Time — время создания нового соединения
+   - Connection Usage Time — среднее время использования соединения
+
+### Полезные функции Grafana
+
+**Time Range:**
+- Последние 5 минут — реал-тайм мониторинг
+- Последний час — анализ недавних инцидентов
+- Последние 24 часа — дневные паттерны
+
+**Refresh:**
+- 5s — активный мониторинг
+- 30s — обычный режим
+- Off — анализ истории
+
+**Zoom:**
+- Выдели область на графике для zoom-in
+- Двойной клик — zoom-out
+
+**Legend:**
+- Клик на метрику — скрыть/показать
+- Shift+клик — изолировать метрику
+
+## Практические сценарии
+
+### 1. Медленный эндпоинт
+
+**Признаки:**
+- Request Duration (p95) > 1s для конкретного URI
+- Connection Acquire Time растет
+
+**Диагностика:**
+```promql
+# Найти медленный эндпоинт
+topk(5, histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket[5m])) by (le, uri)))
+
+# Проверить время получения соединения
+histogram_quantile(0.95, rate(hikaricp_connections_acquire_seconds_bucket[1m]))
+```
+
+**Решение:**
+- Оптимизировать SQL запрос
+- Добавить индексы
+- Включить кеширование
+
+### 2. Memory Leak
+
+**Признаки:**
+- Heap memory постоянно растет
+- Частые Full GC паузы
+- OutOfMemoryError в логах
+
+**Диагностика:**
+```promql
+# Рост памяти
+jvm_memory_used_bytes{area="heap"}
+
+# Частота GC
+rate(jvm_gc_pause_seconds_count[1m])
+```
+
+**Решение:**
+- Heap dump анализ (jmap)
+- Проверить кеши и коллекции
+- Закрывать ресурсы (connections, streams)
+
+### 3. Connection Pool Exhausted
+
+**Признаки:**
+- Active connections = Max connections
+- Pending threads > 0
+- Timeouts растут
+- Медленные запросы
+
+**Диагностика:**
+```promql
+# Утилизация пула
+(hikaricp_connections_active / hikaricp_connections_max) * 100
+
+# Ожидающие потоки
+hikaricp_connections_pending
+
+# Таймауты
+rate(hikaricp_connections_timeout_total[1m])
+```
+
+**Решение:**
+- Увеличить `spring.datasource.hikari.maximum-pool-size`
+- Найти медленные запросы
+- Проверить connection leaks (незакрытые соединения)
+
+### 4. Высокая нагрузка
+
+**Признаки:**
+- Request rate резко вырос
+- CPU usage > 80%
+- Response time увеличилось
+
+**Диагностика:**
+```promql
+# Request rate
+sum(rate(http_server_requests_seconds_count[1m]))
+
+# CPU
+system_cpu_usage
+
+# Response time
+histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket[5m])) by (le))
+```
+
+**Решение:**
+- Горизонтальное масштабирование (больше инстансов)
+- Rate limiting
+- Кеширование частых запросов
+
+## Настройка алертов (опционально)
+
+Создай файл `prometheus-alerts.yml`:
+
+```yaml
+groups:
+  - name: app_alerts
+    interval: 30s
+    rules:
+      - alert: HighErrorRate
+        expr: rate(http_server_requests_seconds_count{status=~"5.."}[1m]) > 0.1
+        for: 1m
+        labels:
+          severity: critical
+        annotations:
+          summary: "High 5xx error rate"
+
+      - alert: HighMemoryUsage
+        expr: (jvm_memory_used_bytes{area="heap"} / jvm_memory_max_bytes{area="heap"}) > 0.9
+        for: 2m
+        labels:
+          severity: warning
+        annotations:
+          summary: "JVM heap usage > 90%"
+
+      - alert: ConnectionPoolExhausted
+        expr: (hikaricp_connections_active / hikaricp_connections_max) > 0.9
+        for: 1m
+        labels:
+          severity: critical
+        annotations:
+          summary: "Connection pool almost full"
+
+      - alert: SlowEndpoint
+        expr: histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket[5m])) by (le, uri)) > 2
+        for: 5m
+        labels:
+          severity: warning
+        annotations:
+          summary: "Endpoint p95 latency > 2s"
+```
+
+Добавь в `prometheus.yml`:
+```yaml
+rule_files:
+  - /etc/prometheus/prometheus-alerts.yml
+```
+
+## Best Practices
+
+1. **Регулярно проверяй метрики** — открывай Grafana хотя бы раз в день
+2. **Настрой алерты** — получай уведомления о проблемах
+3. **Анализируй тренды** — сравнивай метрики по неделям
+4. **Документируй инциденты** — записывай что пошло не так и как исправил
+5. **Тестируй под нагрузкой** — используй JMeter/Gatling + метрики для нагрузочного тестирования
+6. **Не игнорируй warning** — маленькие проблемы перерастают в большие
+
+## Полезные PromQL запросы
+
+```promql
+# Top 5 медленных эндпоинтов
+topk(5, histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket[5m])) by (le, uri)))
+
+# Request rate по методам
+sum(rate(http_server_requests_seconds_count[1m])) by (method)
+
+# Error rate %
+(sum(rate(http_server_requests_seconds_count{status=~"[45].."}[1m])) / sum(rate(http_server_requests_seconds_count[1m]))) * 100
+
+# Memory growth rate (MB/hour)
+rate(jvm_memory_used_bytes{area="heap"}[1h]) * 3600 / 1024 / 1024
+
+# Database connection wait time
+sum(rate(hikaricp_connections_pending[1m]))
+
+# Thread count trend
+jvm_threads_live_threads - jvm_threads_live_threads offset 1h
+```
@@ -0,0 +1,38 @@
+# Todo REST API
+
+Spring Boot приложение для управления задачами.
+
+## Эндпоинты
+
+- `GET /api/tasks/{id}` — получить задачу по ID
+- `POST /api/tasks` — создать задачу
+- `PUT /api/tasks/{id}` — обновить задачу
+- `DELETE /api/tasks/{id}` — удалить задачу
+
+## Запуск
+
+```bash
+docker-compose up --build
+```
+
+Приложение доступно на `http://localhost:8080`
+
+## Пример запроса
+
+```bash
+# Создать задачу
+curl -X POST http://localhost:8080/api/tasks \
+  -H "Content-Type: application/json" \
+  -d '{"title": "Test task", "description": "Description", "completed": false}'
+
+# Получить задачу
+curl http://localhost:8080/api/tasks/1
+
+# Обновить задачу
+curl -X PUT http://localhost:8080/api/tasks/1 \
+  -H "Content-Type: application/json" \
+  -d '{"title": "Updated", "description": "New description", "completed": true}'
+
+# Удалить задачу
+curl -X DELETE http://localhost:8080/api/tasks/1
+```
@@ -0,0 +1,38 @@
+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '4.1.1'
+	id 'io.spring.dependency-management' version '1.1.7'
+}
+
+group = 'ru.dxunvrs'
+version = '0.0.1-SNAPSHOT'
+
+java {
+	toolchain {
+		languageVersion = JavaLanguageVersion.of(21)
+	}
+}
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
+	implementation 'org.springframework.boot:spring-boot-starter-validation'
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'org.springframework.boot:spring-boot-starter-actuator'
+	implementation 'io.micrometer:micrometer-registry-prometheus'
+	compileOnly 'org.projectlombok:lombok'
+	runtimeOnly 'org.postgresql:postgresql'
+	annotationProcessor 'org.projectlombok:lombok'
+	testImplementation 'org.springframework.boot:spring-boot-starter-validation-test'
+	testImplementation 'org.springframework.boot:spring-boot-starter-webmvc-test'
+	testCompileOnly 'org.projectlombok:lombok'
+	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+	testAnnotationProcessor 'org.projectlombok:lombok'
+}
+
+tasks.named('test') {
+	useJUnitPlatform()
+}
@@ -0,0 +1,73 @@
+version: '3.8'
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    container_name: todo-postgres
+    environment:
+      POSTGRES_DB: tododb
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - "5432:5432"
+    volumes:
+      - postgres-data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    container_name: todo-app
+    environment:
+      DB_HOST: postgres
+      DB_PORT: 5432
+      DB_NAME: tododb
+      DB_USER: postgres
+      DB_PASSWORD: postgres
+    ports:
+      - "8080:8080"
+    depends_on:
+      postgres:
+        condition: service_healthy
+
+  prometheus:
+    image: prom/prometheus:latest
+    container_name: todo-prometheus
+    volumes:
+      - ./prometheus.yml:/etc/prometheus/prometheus.yml
+      - prometheus-data:/prometheus
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+    ports:
+      - "9090:9090"
+    depends_on:
+      - app
+
+  grafana:
+    image: grafana/grafana:latest
+    container_name: todo-grafana
+    volumes:
+      - grafana-data:/var/lib/grafana
+      - ./grafana-datasource.yml:/etc/grafana/provisioning/datasources/datasource.yml
+      - ./grafana-dashboard-provider.yml:/etc/grafana/provisioning/dashboards/provider.yml
+      - ./grafana-dashboard-app.json:/etc/grafana/provisioning/dashboards/app.json
+      - ./grafana-dashboard-db.json:/etc/grafana/provisioning/dashboards/db.json
+    environment:
+      - GF_SECURITY_ADMIN_USER=admin
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+      - GF_USERS_ALLOW_SIGN_UP=false
+    ports:
+      - "3000:3000"
+    depends_on:
+      - prometheus
+
+volumes:
+  postgres-data:
+  prometheus-data:
+  grafana-data:
@@ -0,0 +1,9 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.1-bin.zip
+networkTimeout=10000
+retries=0
+retryBackOffMs=500
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   gradlew start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh gradlew
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/3d91ce3b8caaf77ad09f381f43615b715b53f72c/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
@@ -0,0 +1,82 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  gradlew startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables, and ensure extensions are enabled
+setlocal EnableExtensions
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute gradlew
+@rem endlocal doesn't take effect until after the line is parsed and variables are expanded
+@rem which allows us to clear the local environment before executing the java command
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
+
+:exitWithErrorLevel
+@rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
+"%COMSPEC%" /c exit %ERRORLEVEL%
@@ -0,0 +1,195 @@
+{
+  "dashboard": {
+    "title": "Spring Boot Application Metrics",
+    "tags": ["spring-boot", "todo-app"],
+    "timezone": "browser",
+    "panels": [
+      {
+        "id": 1,
+        "title": "HTTP Request Rate",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 0, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(http_server_requests_seconds_count{application=\"todo\"}[1m])",
+            "legendFormat": "{{method}} {{uri}} - {{status}}"
+          }
+        ],
+        "yaxes": [
+          {"format": "reqps", "label": "Requests/sec"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 2,
+        "title": "HTTP Request Duration (p95, p99)",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 0, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "histogram_quantile(0.95, sum(rate(http_server_requests_seconds_bucket{application=\"todo\"}[5m])) by (le, uri))",
+            "legendFormat": "p95 - {{uri}}"
+          },
+          {
+            "expr": "histogram_quantile(0.99, sum(rate(http_server_requests_seconds_bucket{application=\"todo\"}[5m])) by (le, uri))",
+            "legendFormat": "p99 - {{uri}}"
+          }
+        ],
+        "yaxes": [
+          {"format": "s", "label": "Duration"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 3,
+        "title": "HTTP Status Codes",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 8, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "sum(rate(http_server_requests_seconds_count{application=\"todo\"}[1m])) by (status)",
+            "legendFormat": "{{status}}"
+          }
+        ],
+        "yaxes": [
+          {"format": "reqps"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 4,
+        "title": "JVM Memory Used",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 8, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "jvm_memory_used_bytes{application=\"todo\", area=\"heap\"}",
+            "legendFormat": "Heap"
+          },
+          {
+            "expr": "jvm_memory_used_bytes{application=\"todo\", area=\"nonheap\"}",
+            "legendFormat": "Non-Heap"
+          },
+          {
+            "expr": "jvm_memory_max_bytes{application=\"todo\", area=\"heap\"}",
+            "legendFormat": "Heap Max"
+          }
+        ],
+        "yaxes": [
+          {"format": "bytes"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 5,
+        "title": "Database Connection Pool",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 16, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "hikaricp_connections_active{application=\"todo\"}",
+            "legendFormat": "Active"
+          },
+          {
+            "expr": "hikaricp_connections_idle{application=\"todo\"}",
+            "legendFormat": "Idle"
+          },
+          {
+            "expr": "hikaricp_connections{application=\"todo\"}",
+            "legendFormat": "Total"
+          },
+          {
+            "expr": "hikaricp_connections_max{application=\"todo\"}",
+            "legendFormat": "Max"
+          }
+        ],
+        "yaxes": [
+          {"format": "short", "label": "Connections"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 6,
+        "title": "Database Connection Acquire Time",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 16, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(hikaricp_connections_acquire_seconds_sum{application=\"todo\"}[1m]) / rate(hikaricp_connections_acquire_seconds_count{application=\"todo\"}[1m])",
+            "legendFormat": "Avg Acquire Time"
+          }
+        ],
+        "yaxes": [
+          {"format": "s"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 7,
+        "title": "JVM Threads",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 24, "w": 8, "h": 8},
+        "targets": [
+          {
+            "expr": "jvm_threads_live_threads{application=\"todo\"}",
+            "legendFormat": "Live"
+          },
+          {
+            "expr": "jvm_threads_daemon_threads{application=\"todo\"}",
+            "legendFormat": "Daemon"
+          },
+          {
+            "expr": "jvm_threads_peak_threads{application=\"todo\"}",
+            "legendFormat": "Peak"
+          }
+        ],
+        "yaxes": [
+          {"format": "short", "label": "Threads"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 8,
+        "title": "GC Pause Time",
+        "type": "graph",
+        "gridPos": {"x": 8, "y": 24, "w": 8, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(jvm_gc_pause_seconds_sum{application=\"todo\"}[1m])",
+            "legendFormat": "{{action}} - {{cause}}"
+          }
+        ],
+        "yaxes": [
+          {"format": "s", "label": "GC Time"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 9,
+        "title": "System CPU Usage",
+        "type": "graph",
+        "gridPos": {"x": 16, "y": 24, "w": 8, "h": 8},
+        "targets": [
+          {
+            "expr": "system_cpu_usage{application=\"todo\"}",
+            "legendFormat": "System"
+          },
+          {
+            "expr": "process_cpu_usage{application=\"todo\"}",
+            "legendFormat": "Process"
+          }
+        ],
+        "yaxes": [
+          {"format": "percentunit", "label": "CPU"},
+          {"format": "short"}
+        ]
+      }
+    ],
+    "refresh": "5s",
+    "time": {
+      "from": "now-15m",
+      "to": "now"
+    }
+  },
+  "overwrite": true
+}
@@ -0,0 +1,187 @@
+{
+  "dashboard": {
+    "title": "PostgreSQL & HikariCP Monitoring",
+    "tags": ["database", "postgres", "hikaricp"],
+    "timezone": "browser",
+    "panels": [
+      {
+        "id": 1,
+        "title": "Connection Pool Status",
+        "type": "stat",
+        "gridPos": {"x": 0, "y": 0, "w": 6, "h": 4},
+        "targets": [
+          {
+            "expr": "hikaricp_connections_active{application=\"todo\"}",
+            "legendFormat": "Active"
+          }
+        ],
+        "options": {
+          "colorMode": "value",
+          "graphMode": "area"
+        }
+      },
+      {
+        "id": 2,
+        "title": "Idle Connections",
+        "type": "stat",
+        "gridPos": {"x": 6, "y": 0, "w": 6, "h": 4},
+        "targets": [
+          {
+            "expr": "hikaricp_connections_idle{application=\"todo\"}",
+            "legendFormat": "Idle"
+          }
+        ],
+        "options": {
+          "colorMode": "value",
+          "graphMode": "area"
+        }
+      },
+      {
+        "id": 3,
+        "title": "Total Connections",
+        "type": "stat",
+        "gridPos": {"x": 12, "y": 0, "w": 6, "h": 4},
+        "targets": [
+          {
+            "expr": "hikaricp_connections{application=\"todo\"}",
+            "legendFormat": "Total"
+          }
+        ],
+        "options": {
+          "colorMode": "value",
+          "graphMode": "area"
+        }
+      },
+      {
+        "id": 4,
+        "title": "Pending Threads",
+        "type": "stat",
+        "gridPos": {"x": 18, "y": 0, "w": 6, "h": 4},
+        "targets": [
+          {
+            "expr": "hikaricp_connections_pending{application=\"todo\"}",
+            "legendFormat": "Pending"
+          }
+        ],
+        "options": {
+          "colorMode": "value",
+          "graphMode": "area"
+        }
+      },
+      {
+        "id": 5,
+        "title": "Connection Pool Utilization (%)",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 4, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "(hikaricp_connections_active{application=\"todo\"} / hikaricp_connections_max{application=\"todo\"}) * 100",
+            "legendFormat": "Active %"
+          },
+          {
+            "expr": "(hikaricp_connections{application=\"todo\"} / hikaricp_connections_max{application=\"todo\"}) * 100",
+            "legendFormat": "Total %"
+          }
+        ],
+        "yaxes": [
+          {"format": "percent", "label": "Utilization", "min": 0, "max": 100},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 6,
+        "title": "Connection Acquire Time",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 4, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "histogram_quantile(0.5, rate(hikaricp_connections_acquire_seconds_bucket{application=\"todo\"}[1m]))",
+            "legendFormat": "p50"
+          },
+          {
+            "expr": "histogram_quantile(0.95, rate(hikaricp_connections_acquire_seconds_bucket{application=\"todo\"}[1m]))",
+            "legendFormat": "p95"
+          },
+          {
+            "expr": "histogram_quantile(0.99, rate(hikaricp_connections_acquire_seconds_bucket{application=\"todo\"}[1m]))",
+            "legendFormat": "p99"
+          }
+        ],
+        "yaxes": [
+          {"format": "s", "label": "Time"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 7,
+        "title": "Connection Timeout Count",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 12, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(hikaricp_connections_timeout_total{application=\"todo\"}[1m])",
+            "legendFormat": "Timeouts/sec"
+          }
+        ],
+        "yaxes": [
+          {"format": "short"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 8,
+        "title": "Connection Creation Time",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 12, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(hikaricp_connections_creation_seconds_sum{application=\"todo\"}[1m]) / rate(hikaricp_connections_creation_seconds_count{application=\"todo\"}[1m])",
+            "legendFormat": "Avg Creation Time"
+          }
+        ],
+        "yaxes": [
+          {"format": "s"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 9,
+        "title": "Connection Usage Time",
+        "type": "graph",
+        "gridPos": {"x": 0, "y": 20, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(hikaricp_connections_usage_seconds_sum{application=\"todo\"}[1m]) / rate(hikaricp_connections_usage_seconds_count{application=\"todo\"}[1m])",
+            "legendFormat": "Avg Usage Time"
+          }
+        ],
+        "yaxes": [
+          {"format": "s"},
+          {"format": "short"}
+        ]
+      },
+      {
+        "id": 10,
+        "title": "JDBC Queries Rate",
+        "type": "graph",
+        "gridPos": {"x": 12, "y": 20, "w": 12, "h": 8},
+        "targets": [
+          {
+            "expr": "rate(jdbc_connections_active{application=\"todo\"}[1m])",
+            "legendFormat": "Active JDBC Connections"
+          }
+        ],
+        "yaxes": [
+          {"format": "short"},
+          {"format": "short"}
+        ]
+      }
+    ],
+    "refresh": "5s",
+    "time": {
+      "from": "now-15m",
+      "to": "now"
+    }
+  },
+  "overwrite": true
+}
@@ -0,0 +1,12 @@
+apiVersion: 1
+
+providers:
+  - name: 'Default'
+    orgId: 1
+    folder: ''
+    type: file
+    disableDeletion: false
+    updateIntervalSeconds: 10
+    allowUiUpdates: true
+    options:
+      path: /etc/grafana/provisioning/dashboards
@@ -0,0 +1,9 @@
+apiVersion: 1
+
+datasources:
+  - name: Prometheus
+    type: prometheus
+    access: proxy
+    url: http://prometheus:9090
+    isDefault: true
+    editable: true
@@ -0,0 +1,6 @@
+{
+  "name": "todo",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}
@@ -0,0 +1 @@
+{}
@@ -0,0 +1,9 @@
+global:
+  scrape_interval: 15s
+  evaluation_interval: 15s
+
+scrape_configs:
+  - job_name: 'spring-boot-app'
+    metrics_path: '/actuator/prometheus'
+    static_configs:
+      - targets: ['app:8080']
@@ -0,0 +1 @@
+rootProject.name = 'todo'
@@ -0,0 +1,13 @@
+package ru.dxunvrs.todo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class TodoApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(TodoApplication.class, args);
+	}
+
+}
@@ -0,0 +1,45 @@
+package ru.dxunvrs.todo.controller;
+
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import ru.dxunvrs.todo.dto.TaskCreateRequest;
+import ru.dxunvrs.todo.dto.TaskResponse;
+import ru.dxunvrs.todo.dto.TaskUpdateRequest;
+import ru.dxunvrs.todo.service.TaskService;
+
+@RestController
+@RequestMapping("/api/tasks")
+@RequiredArgsConstructor
+public class TaskController {
+
+    private final TaskService taskService;
+
+    @GetMapping("/{id}")
+    public ResponseEntity<TaskResponse> getTask(@PathVariable Long id) {
+        TaskResponse response = taskService.getById(id);
+        return ResponseEntity.ok(response);
+    }
+
+    @PostMapping
+    public ResponseEntity<TaskResponse> createTask(@Valid @RequestBody TaskCreateRequest request) {
+        TaskResponse response = taskService.create(request);
+        return ResponseEntity.status(HttpStatus.CREATED).body(response);
+    }
+
+    @PutMapping("/{id}")
+    public ResponseEntity<TaskResponse> updateTask(
+            @PathVariable Long id,
+            @Valid @RequestBody TaskUpdateRequest request) {
+        TaskResponse response = taskService.update(id, request);
+        return ResponseEntity.ok(response);
+    }
+
+    @DeleteMapping("/{id}")
+    public ResponseEntity<Void> deleteTask(@PathVariable Long id) {
+        taskService.delete(id);
+        return ResponseEntity.noContent().build();
+    }
+}
@@ -0,0 +1,19 @@
+package ru.dxunvrs.todo.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class TaskCreateRequest {
+
+    @NotBlank(message = "Title is required")
+    private String title;
+
+    private String description;
+
+    private Boolean completed;
+}
@@ -0,0 +1,20 @@
+package ru.dxunvrs.todo.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class TaskResponse {
+
+    private Long id;
+    private String title;
+    private String description;
+    private Boolean completed;
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+}
@@ -0,0 +1,19 @@
+package ru.dxunvrs.todo.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class TaskUpdateRequest {
+
+    @NotBlank(message = "Title is required")
+    private String title;
+
+    private String description;
+
+    private Boolean completed;
+}
@@ -0,0 +1,46 @@
+package ru.dxunvrs.todo.entity;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Table(name = "tasks")
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class Task {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(nullable = false)
+    private String title;
+
+    @Column(columnDefinition = "TEXT")
+    private String description;
+
+    @Column(nullable = false)
+    private Boolean completed = false;
+
+    @Column(name = "created_at", nullable = false, updatable = false)
+    private LocalDateTime createdAt;
+
+    @Column(name = "updated_at")
+    private LocalDateTime updatedAt;
+
+    @PrePersist
+    protected void onCreate() {
+        createdAt = LocalDateTime.now();
+        updatedAt = LocalDateTime.now();
+    }
+
+    @PreUpdate
+    protected void onUpdate() {
+        updatedAt = LocalDateTime.now();
+    }
+}
@@ -0,0 +1,58 @@
+package ru.dxunvrs.todo.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import java.time.LocalDateTime;
+import java.util.HashMap;
+import java.util.Map;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(TaskNotFoundException.class)
+    public ResponseEntity<ErrorResponse> handleTaskNotFound(TaskNotFoundException ex) {
+        ErrorResponse error = new ErrorResponse(
+                HttpStatus.NOT_FOUND.value(),
+                ex.getMessage(),
+                LocalDateTime.now()
+        );
+        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
+    }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<ValidationErrorResponse> handleValidation(MethodArgumentNotValidException ex) {
+        Map<String, String> errors = new HashMap<>();
+        ex.getBindingResult().getAllErrors().forEach(error -> {
+            String fieldName = ((FieldError) error).getField();
+            String message = error.getDefaultMessage();
+            errors.put(fieldName, message);
+        });
+        
+        ValidationErrorResponse response = new ValidationErrorResponse(
+                HttpStatus.BAD_REQUEST.value(),
+                "Validation failed",
+                LocalDateTime.now(),
+                errors
+        );
+        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(response);
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ErrorResponse> handleGeneral(Exception ex) {
+        ErrorResponse error = new ErrorResponse(
+                HttpStatus.INTERNAL_SERVER_ERROR.value(),
+                "Internal server error",
+                LocalDateTime.now()
+        );
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(error);
+    }
+
+    record ErrorResponse(int status, String message, LocalDateTime timestamp) {}
+    
+    record ValidationErrorResponse(int status, String message, LocalDateTime timestamp, Map<String, String> errors) {}
+}
@@ -0,0 +1,7 @@
+package ru.dxunvrs.todo.exception;
+
+public class TaskNotFoundException extends RuntimeException {
+    public TaskNotFoundException(String message) {
+        super(message);
+    }
+}
@@ -0,0 +1,38 @@
+package ru.dxunvrs.todo.mapper;
+
+import org.springframework.stereotype.Component;
+import ru.dxunvrs.todo.dto.TaskCreateRequest;
+import ru.dxunvrs.todo.dto.TaskResponse;
+import ru.dxunvrs.todo.dto.TaskUpdateRequest;
+import ru.dxunvrs.todo.entity.Task;
+
+@Component
+public class TaskMapper {
+
+    public Task toEntity(TaskCreateRequest request) {
+        Task task = new Task();
+        task.setTitle(request.getTitle());
+        task.setDescription(request.getDescription());
+        task.setCompleted(request.getCompleted() != null ? request.getCompleted() : false);
+        return task;
+    }
+
+    public void updateEntity(Task task, TaskUpdateRequest request) {
+        task.setTitle(request.getTitle());
+        task.setDescription(request.getDescription());
+        if (request.getCompleted() != null) {
+            task.setCompleted(request.getCompleted());
+        }
+    }
+
+    public TaskResponse toResponse(Task task) {
+        return new TaskResponse(
+                task.getId(),
+                task.getTitle(),
+                task.getDescription(),
+                task.getCompleted(),
+                task.getCreatedAt(),
+                task.getUpdatedAt()
+        );
+    }
+}
@@ -0,0 +1,9 @@
+package ru.dxunvrs.todo.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+import ru.dxunvrs.todo.entity.Task;
+
+@Repository
+public interface TaskRepository extends JpaRepository<Task, Long> {
+}
@@ -0,0 +1,16 @@
+package ru.dxunvrs.todo.service;
+
+import ru.dxunvrs.todo.dto.TaskCreateRequest;
+import ru.dxunvrs.todo.dto.TaskResponse;
+import ru.dxunvrs.todo.dto.TaskUpdateRequest;
+
+public interface TaskService {
+
+    TaskResponse getById(Long id);
+
+    TaskResponse create(TaskCreateRequest request);
+
+    TaskResponse update(Long id, TaskUpdateRequest request);
+
+    void delete(Long id);
+}
@@ -0,0 +1,55 @@
+package ru.dxunvrs.todo.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import ru.dxunvrs.todo.dto.TaskCreateRequest;
+import ru.dxunvrs.todo.dto.TaskResponse;
+import ru.dxunvrs.todo.dto.TaskUpdateRequest;
+import ru.dxunvrs.todo.entity.Task;
+import ru.dxunvrs.todo.exception.TaskNotFoundException;
+import ru.dxunvrs.todo.mapper.TaskMapper;
+import ru.dxunvrs.todo.repository.TaskRepository;
+
+@Service
+@RequiredArgsConstructor
+public class TaskServiceImpl implements TaskService {
+
+    private final TaskRepository taskRepository;
+    private final TaskMapper taskMapper;
+
+    @Override
+    @Transactional(readOnly = true)
+    public TaskResponse getById(Long id) {
+        Task task = taskRepository.findById(id)
+                .orElseThrow(() -> new TaskNotFoundException("Task not found with id: " + id));
+        return taskMapper.toResponse(task);
+    }
+
+    @Override
+    @Transactional
+    public TaskResponse create(TaskCreateRequest request) {
+        Task task = taskMapper.toEntity(request);
+        Task saved = taskRepository.save(task);
+        return taskMapper.toResponse(saved);
+    }
+
+    @Override
+    @Transactional
+    public TaskResponse update(Long id, TaskUpdateRequest request) {
+        Task task = taskRepository.findById(id)
+                .orElseThrow(() -> new TaskNotFoundException("Task not found with id: " + id));
+        taskMapper.updateEntity(task, request);
+        Task updated = taskRepository.save(task);
+        return taskMapper.toResponse(updated);
+    }
+
+    @Override
+    @Transactional
+    public void delete(Long id) {
+        if (!taskRepository.existsById(id)) {
+            throw new TaskNotFoundException("Task not found with id: " + id);
+        }
+        taskRepository.deleteById(id);
+    }
+}
@@ -0,0 +1,24 @@
+spring.application.name=todo
+
+spring.datasource.url=jdbc:postgresql://${DB_HOST:localhost}:${DB_PORT:5432}/${DB_NAME:tododb}
+spring.datasource.username=${DB_USER:postgres}
+spring.datasource.password=${DB_PASSWORD:postgres}
+spring.datasource.driver-class-name=org.postgresql.Driver
+
+spring.datasource.hikari.maximum-pool-size=10
+spring.datasource.hikari.minimum-idle=5
+spring.datasource.hikari.connection-timeout=30000
+spring.datasource.hikari.idle-timeout=600000
+spring.datasource.hikari.max-lifetime=1800000
+
+spring.jpa.hibernate.ddl-auto=update
+spring.jpa.show-sql=false
+spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
+spring.jpa.properties.hibernate.format_sql=true
+
+management.endpoints.web.exposure.include=health,info,metrics,prometheus
+management.endpoint.health.show-details=always
+management.endpoint.prometheus.enabled=true
+management.metrics.export.prometheus.enabled=true
+management.metrics.tags.application=${spring.application.name}
+management.metrics.distribution.percentiles-histogram.http.server.requests=true
@@ -0,0 +1,13 @@
+package ru.dxunvrs.todo;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class TodoApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}