diff --git a/.gitignore b/.gitignore
index f74d1ab..7899570 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
 /stubs
-/vendor
+vendor
 composer.lock
diff --git a/example/opentelemetry/README.md b/example/opentelemetry/README.md
new file mode 100644
index 0000000..15d0149
--- /dev/null
+++ b/example/opentelemetry/README.md
@@ -0,0 +1,45 @@
+# Example for Relay OpenTelemetry instrumentation
+
+This example demonstrates how to monitor Redis using [OpenTelemetry](https://opentelemetry.io/) and
+[Uptrace](https://uptrace.dev/get/open-source-apm.html. It requires Docker to start Redis Server and Uptrace.
+
+**Step 1**. Download the example using Git:
+
+```shell
+git clone https://github.com/cachewerk/relay.git
+cd example/opentelemetry
+```
+
+**Step 2**. Start the services using Docker:
+
+```shell
+docker-compose up -d
+```
+
+**Step 3**. Make sure Redis and Uptrace are running:
+
+```shell
+docker-compose logs redis
+docker-compose logs uptrace
+```
+
+**Step 4**. Install dependencies and run the Relay example:
+
+```shell
+composer install
+php main.php
+```
+
+**Step 5**. Follow the link from the CLI to view the trace:
+
+```shell
+php main.php
+trace: http://localhost:14318/traces/ee029d8782242c8ed38b16d961093b35
+```
+
+![Relay trace](./image/relay-trace.png)
+
+You can also open Uptrace UI at [http://localhost:14318](http://localhost:14318) to view available
+spans, logs, and metrics.
+
+See [Monitoring Relay Redis client with OpenTelemetry](https://uptrace.dev/blog/posts/relay-cache-opentelemetry.html).
diff --git a/example/opentelemetry/composer.json b/example/opentelemetry/composer.json
new file mode 100644
index 0000000..daacfc8
--- /dev/null
+++ b/example/opentelemetry/composer.json
@@ -0,0 +1,19 @@
+{
+  "name": "relay/example-opentelemetry",
+  "authors": [
+    {
+      "name": "Vladimir Mihailenco",
+      "email": "vladimir.webdev@gmail.com"
+    }
+  ],
+  "require": {
+    "cachewerk/relay": "^0.5.1",
+    "uptrace/uptrace": "0.1.2"
+  },
+  "autoload": {
+    "psr-4": {
+      "CacheWerk\\Relay\\": "../../src/"
+    }
+  },
+  "minimum-stability": "dev"
+}
diff --git a/example/opentelemetry/config/alertmanager.yml b/example/opentelemetry/config/alertmanager.yml
new file mode 100644
index 0000000..ac3e340
--- /dev/null
+++ b/example/opentelemetry/config/alertmanager.yml
@@ -0,0 +1,53 @@
+# See https://prometheus.io/docs/alerting/latest/configuration/ for details.
+
+global:
+  # The smarthost and SMTP sender used for mail notifications.
+  smtp_smarthost: "mailhog:1025"
+  smtp_from: "alertmanager@example.com"
+  smtp_require_tls: false
+
+receivers:
+  - name: "team-X"
+    email_configs:
+      - to: "some-receiver@example.com"
+        send_resolved: true
+
+# The root route on which each incoming alert enters.
+route:
+  # The labels by which incoming alerts are grouped together. For example,
+  # multiple alerts coming in for cluster=A and alertname=LatencyHigh would
+  # be batched into a single group.
+  group_by: ["alertname", "cluster", "service"]
+
+  # When a new group of alerts is created by an incoming alert, wait at
+  # least 'group_wait' to send the initial notification.
+  # This way ensures that you get multiple alerts for the same group that start
+  # firing shortly after another are batched together on the first
+  # notification.
+  group_wait: 30s
+
+  # When the first notification was sent, wait 'group_interval' to send a batch
+  # of new alerts that started firing for that group.
+  group_interval: 5m
+
+  # If an alert has successfully been sent, wait 'repeat_interval' to
+  # resend them.
+  repeat_interval: 3h
+
+  # A default receiver
+  receiver: team-X
+
+  # All the above attributes are inherited by all child routes and can
+  # overwritten on each.
+
+  # The child route trees.
+  routes:
+    # This route matches error alerts created from spans or logs.
+    - matchers:
+        - alert_kind="error"
+      group_interval: 24h
+      receiver: team-X
+
+# The directory from which notification templates are read.
+templates:
+  - "/etc/alertmanager/template/*.tmpl"
diff --git a/example/opentelemetry/config/otel-collector.yaml b/example/opentelemetry/config/otel-collector.yaml
new file mode 100644
index 0000000..b44dd1f
--- /dev/null
+++ b/example/opentelemetry/config/otel-collector.yaml
@@ -0,0 +1,68 @@
+extensions:
+  health_check:
+  pprof:
+    endpoint: 0.0.0.0:1777
+  zpages:
+    endpoint: 0.0.0.0:55679
+
+receivers:
+  otlp:
+    protocols:
+      grpc:
+      http:
+  hostmetrics:
+    collection_interval: 10s
+    scrapers:
+      cpu:
+      disk:
+      load:
+      filesystem:
+      memory:
+      network:
+      paging:
+  redis:
+    endpoint: "redis-server:6379"
+    collection_interval: 10s
+  jaeger:
+    protocols:
+      grpc:
+
+processors:
+  resourcedetection:
+    detectors: ["system"]
+  batch:
+    send_batch_size: 10000
+    timeout: 10s
+
+exporters:
+  logging:
+    logLevel: debug
+  otlp:
+    endpoint: uptrace:14317
+    tls:
+      insecure: true
+    headers: { "uptrace-dsn": "http://project2_secret_token@localhost:14317/2" }
+
+service:
+  # telemetry:
+  #   logs:
+  #     level: DEBUG
+  pipelines:
+    traces:
+      receivers: [otlp, jaeger]
+      processors: [batch]
+      exporters: [otlp, logging]
+    metrics:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp]
+    metrics/hostmetrics:
+      receivers: [hostmetrics, redis]
+      processors: [batch, resourcedetection]
+      exporters: [otlp]
+    logs:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp]
+
+  extensions: [health_check, pprof, zpages]
diff --git a/example/opentelemetry/config/vector.toml b/example/opentelemetry/config/vector.toml
new file mode 100644
index 0000000..10db91d
--- /dev/null
+++ b/example/opentelemetry/config/vector.toml
@@ -0,0 +1,39 @@
+[sources.syslog_logs]
+type = "demo_logs"
+format = "syslog"
+interval = 0.1
+
+[sources.apache_common_logs]
+type = "demo_logs"
+format = "apache_common"
+interval = 0.1
+
+[sources.apache_error_logs]
+type = "demo_logs"
+format = "apache_error"
+interval = 0.1
+
+[sources.json_logs]
+type = "demo_logs"
+format = "json"
+interval = 0.1
+
+# Parse Syslog logs
+# See the Vector Remap Language reference for more info: https://vrl.dev
+[transforms.parse_logs]
+type = "remap"
+inputs = ["syslog_logs"]
+source = '''
+. = parse_syslog!(string!(.message))
+'''
+
+# Export data to Uptrace.
+[sinks.uptrace]
+type = "http"
+inputs = ["parse_logs", "apache_common_logs", "apache_error_logs", "json_logs"]
+encoding.codec = "json"
+framing.method = "newline_delimited"
+compression = "gzip"
+uri = "http://uptrace:14318/api/v1/vector/logs"
+#uri = "https://api.uptrace.dev/api/v1/vector/logs"
+headers.uptrace-dsn = "http://project2_secret_token@localhost:14317/2"
diff --git a/example/opentelemetry/docker-compose.yml b/example/opentelemetry/docker-compose.yml
new file mode 100644
index 0000000..4b47375
--- /dev/null
+++ b/example/opentelemetry/docker-compose.yml
@@ -0,0 +1,81 @@
+version: "3"
+
+services:
+  clickhouse:
+    image: clickhouse/clickhouse-server:22.10
+    restart: on-failure
+    environment:
+      CLICKHOUSE_DB: uptrace
+    healthcheck:
+      test: ["CMD", "wget", "--spider", "-q", "localhost:8123/ping"]
+      interval: 1s
+      timeout: 1s
+      retries: 30
+    volumes:
+      - ch_data:/var/lib/clickhouse
+    ports:
+      - "8123:8123"
+      - "9000:9000"
+
+  uptrace:
+    image: "uptrace/uptrace:1.2.4"
+    #image: "uptrace/uptrace-dev:latest"
+    restart: on-failure
+    volumes:
+      - uptrace_data:/var/lib/uptrace
+      - ./uptrace.yml:/etc/uptrace/uptrace.yml
+    #environment:
+    #  - DEBUG=2
+    ports:
+      - "14317:14317"
+      - "14318:14318"
+    depends_on:
+      clickhouse:
+        condition: service_healthy
+
+  otel-collector:
+    image: otel/opentelemetry-collector-contrib:0.59.0
+    restart: on-failure
+    volumes:
+      - ./config/otel-collector.yaml:/etc/otelcol-contrib/config.yaml
+    ports:
+      - "4317:4317"
+      - "4318:4318"
+
+  redis-server:
+    image: redis
+    ports:
+      - "6379:6379"
+  redis-cli:
+    image: redis
+
+  vector:
+    image: timberio/vector:0.24.X-alpine
+    volumes:
+      - ./config/vector.toml:/etc/vector/vector.toml:ro
+
+  alertmanager:
+    image: prom/alertmanager:v0.24.0
+    restart: on-failure
+    volumes:
+      - ./config/alertmanager.yml:/etc/alertmanager/config.yml
+      - alertmanager_data:/alertmanager
+    ports:
+      - 9093:9093
+    command:
+      - "--config.file=/etc/alertmanager/config.yml"
+      - "--storage.path=/alertmanager"
+
+  mailhog:
+    image: mailhog/mailhog:v1.0.1
+    restart: on-failure
+    ports:
+      - "8025:8025"
+
+volumes:
+  uptrace_data:
+    driver: local
+  ch_data:
+    driver: local
+  alertmanager_data:
+    driver: local
diff --git a/example/opentelemetry/image/metrics.png b/example/opentelemetry/image/metrics.png
new file mode 100644
index 0000000..3927aa0
Binary files /dev/null and b/example/opentelemetry/image/metrics.png differ
diff --git a/example/opentelemetry/image/relay-trace.png b/example/opentelemetry/image/relay-trace.png
new file mode 100644
index 0000000..704eb0c
Binary files /dev/null and b/example/opentelemetry/image/relay-trace.png differ
diff --git a/example/opentelemetry/main.php b/example/opentelemetry/main.php
new file mode 100644
index 0000000..516684c
--- /dev/null
+++ b/example/opentelemetry/main.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+require __DIR__ . '/vendor/autoload.php';
+
+use \CacheWerk\Relay\Psr\Tracing\RelayOpenTelemetry;
+
+$conf = new Uptrace\Config();
+$conf->setDsn('http://project2_secret_token@localhost:14318/2');
+$conf->setServiceName('myservice');
+$conf->setServiceVersion('1.0.0');
+
+$uptrace = new Uptrace\Distro($conf);
+$tracerProvider = $uptrace->createTracerProvider();
+$tracer = $tracerProvider->getTracer('relay/example-opentelemetry');
+
+$redis = new RelayOpenTelemetry(function() {
+    return new Relay\Relay;
+}, $tracerProvider);
+
+$redis->connect('127.0.0.1', 6379);
+
+$span = handleRequest($tracer, $redis);
+echo $uptrace->traceUrl($span) . PHP_EOL;
+
+for ($i = 0; $i <= 1000000; $i++) {
+    handleRequest($tracer, $redis);
+    sleep(1);
+}
+
+// Send buffered spans and free resources.
+$tracerProvider->shutdown();
+
+function handleRequest($tracer, $redis) {
+    $span = $tracer->spanBuilder('handle-request')->startSpan();
+    $spanScope = $span->activate();
+
+    $value = $redis->get('count');
+    $redis->set('counter', (int)$value + 1);
+
+    $redis->multi()
+          ->set('key1', 'val1')
+          ->get('key1')
+          ->set('key2', 'val2')
+          ->get('key2')
+          ->exec();
+
+    $pipe = $redis->pipeline();
+    for ($i = 0; $i <= 100; $i++) {
+        $pipe->set('key' . $i, '');
+    }
+    $pipe->exec();
+
+    $it = NULL;
+    do {
+        // Scan for some keys
+        $arr_keys = $redis->scan($it);
+    } while ($it > 0);
+
+    $spanScope->detach();
+    $span->end();
+
+    return $span;
+}
diff --git a/example/opentelemetry/uptrace.yml b/example/opentelemetry/uptrace.yml
new file mode 100644
index 0000000..33d393a
--- /dev/null
+++ b/example/opentelemetry/uptrace.yml
@@ -0,0 +1,265 @@
+##
+## Uptrace configuration file.
+## See https://uptrace.dev/get/config.html for details.
+##
+## You can use environment variables anywhere in this file, for example:
+##
+##   foo: $FOO
+##   bar: ${BAR}
+##   baz: ${BAZ:default}
+##
+## To escape `$`, use `$$`, for example:
+##
+##   foo: $$FOO_BAR
+##
+
+##
+## ClickHouse database credentials.
+##
+ch:
+  # Connection string for a ClickHouse database. For example:
+  # clickhouse://<user>:<password>@<host>:<port>/<database>?sslmode=disable
+  #
+  # See https://clickhouse.uptrace.dev/guide/golang-clickhouse.html#options
+  dsn: "clickhouse://default:@clickhouse:9000/uptrace?sslmode=disable"
+
+  # Maximum query execution time.
+  max_execution_time: 30s
+
+##
+## A list of pre-configured projects. Each project is fully isolated.
+##
+projects:
+  # Conventionally, the first project is used to monitor Uptrace itself.
+  - id: 1
+    name: Uptrace
+    # Token grants write access to the project. Keep a secret.
+    token: project1_secret_token
+    pinned_attrs:
+      - service
+      - host.name
+      - deployment.environment
+    # Group spans by deployment.environment attribute.
+    group_by_env: false
+    # Group funcs spans by service.name attribute.
+    group_funcs_by_service: false
+
+  # Other projects can be used to monitor your applications.
+  # To monitor micro-services or multiple related services, use a single project.
+  - id: 2
+    name: My project
+    token: project2_secret_token
+    pinned_attrs:
+      - service
+      - host.name
+      - deployment.environment
+    # Group spans by deployment.environment attribute.
+    group_by_env: false
+    # Group funcs spans by service.name attribute.
+    group_funcs_by_service: false
+
+##
+## Create metrics from spans and events.
+##
+metrics_from_spans:
+  - name: uptrace.tracing.spans
+    description: Total number of spans including logs and events
+    instrument: counter
+    unit: 1
+    value: span.count
+    attrs: [span.system, service.name, host.name, span.status_code]
+
+  - name: uptrace.tracing.spans_duration
+    description: Spans duration
+    instrument: histogram
+    unit: microseconds
+    value: span.duration / 1000
+    attrs: [span.system, service.name, host.name]
+    where: span.duration > 0
+
+  - name: uptrace.tracing.error_rate
+    description: Spans error rate
+    instrument: gauge
+    unit: percents
+    value: span.error_count / span.count
+    attrs: [span.system, service.name, host.name]
+
+##
+## Alerting rules for monitoring metrics.
+##
+## See https://uptrace.dev/get/alerting.html for details.
+##
+alerting:
+  rules:
+    - name: Redis is working
+      metrics:
+        - uptrace.tracing.spans as $spans
+      query:
+        - $spans > 0
+        - where system = 'db:redis'
+      for: 5m
+      annotations:
+        summary: "Got {{ $values.spans }} spans from Redis"
+
+    - name: Redis is failing
+      metrics:
+        - uptrace.tracing.spans as $spans
+      query:
+        - $spans{status='error'} > 10
+        - where system = 'db:redis'
+      for: 5m
+
+  # Create alerts from error logs and span events.
+  create_alerts_from_spans:
+    enabled: true
+    labels:
+      alert_kind: error
+
+##
+## To require authentication, uncomment one of the following sections.
+##
+auth:
+  # users:
+  #   - username: uptrace
+  #     password: uptrace
+  #   - username: admin
+  #     password: admin
+
+  # Cloudflare Zero Trust Access (Identity)
+  # See https://developers.cloudflare.com/cloudflare-one/identity/ for more info.
+  # cloudflare:
+  #   # The base URL of the Cloudflare Zero Trust team.
+  #   - team_url: https://myteam.cloudflareaccess.com
+  #     # The Application Audience (AUD) Tag for this application.
+  #     # You can retrieve this from the Cloudflare Zero Trust 'Access' Dashboard.
+  #     audience: bea6df23b944e4a0cd178609ba1bb64dc98dfe1f66ae7b918e563f6cf28b37e0
+
+  # OpenID Connect (Single Sign-On)
+  # oidc:
+  #   # The ID is used in API endpoints, for example, in redirect URL
+  #   # `http://<uptrace-host>/api/v1/sso/<oidc-id>/callback`.
+  #   - id: keycloak
+  #     # Display name for the button in the login form.
+  #     # Default to 'OpenID Connect'
+  #     display_name: Keycloak
+  #     # The base URL for the OIDC provider.
+  #     issuer_url: http://localhost:8080/realms/uptrace
+  #     # The OAuth 2.0 Client ID
+  #     client_id: uptrace
+  #     # The OAuth 2.0 Client Secret
+  #     client_secret: ogbhd8Q0X0e5AZFGSG3m9oirPvnetqkA
+  #     # Additional OAuth 2.0 scopes to request from the OIDC provider.
+  #     # Defaults to 'profile'. 'openid' is requested by default and need not be specified.
+  #     scopes:
+  #       - profile
+  #     # The OIDC UserInfo claim to use as the user's username.
+  #     # Defaults to 'preferred_username'.
+  #     claim: preferred_username
+
+##
+## AlertManager client configuration.
+## See https://uptrace.dev/get/alerting.html for details.
+##
+## Note that this is NOT an AlertManager config and you need to configure AlertManager separately.
+## See https://prometheus.io/docs/alerting/latest/configuration/ for details.
+##
+alertmanager_client:
+  # AlertManager API endpoints that Uptrace uses to manage alerts.
+  urls:
+    - "http://localhost:9093/api/v2/alerts"
+
+##
+## Various options to tweak ClickHouse schema.
+## For changes to take effect, you need reset the ClickHouse database with `ch reset`.
+##
+ch_schema:
+  # Compression codec, for example, LZ4, ZSTD(3), or Default.
+  compression: ZSTD(3)
+
+  # Whether to use ReplicatedMergeTree instead of MergeTree.
+  replicated: false
+
+  # Cluster name for Distributed tables and ON CLUSTER clause.
+  #cluster: uptrace1
+
+  spans:
+    storage_policy: "default"
+    # Delete spans data after 30 days.
+    ttl_delete: 30 DAY
+
+  metrics:
+    storage_policy: "default"
+    # Delete metrics data after 90 days.
+    ttl_delete: 90 DAY
+
+##
+## Addresses on which Uptrace receives gRPC and HTTP requests.
+##
+listen:
+  # OTLP/gRPC API.
+  grpc:
+    addr: ":14317"
+    # tls:
+    #   cert_file: config/tls/uptrace.crt
+    #   key_file: config/tls/uptrace.key
+
+  # OTLP/HTTP API and Uptrace API with UI.
+  http:
+    addr: ":14318"
+    # tls:
+    #   cert_file: config/tls/uptrace.crt
+    #   key_file: config/tls/uptrace.key
+
+##
+## Various options for Uptrace UI.
+##
+site:
+  # Overrides public URL for Vue-powered UI in case you put Uptrace behind a proxy.
+  #addr: 'https://uptrace.mydomain.com'
+
+##
+## Spans processing options.
+##
+spans:
+  # The size of the Go chan used to buffer incoming spans.
+  # If the buffer is full, Uptrace starts to drop spans.
+  #buffer_size: 100000
+
+  # The number of spans to insert in a single query.
+  #batch_size: 10000
+
+##
+## Metrics processing options.
+##
+metrics:
+  # List of attributes to drop for being noisy.
+  drop_attrs:
+    - telemetry.sdk.language
+    - telemetry.sdk.name
+    - telemetry.sdk.version
+
+  # The size of the Go chan used to buffer incoming measures.
+  # If the buffer is full, Uptrace starts to drop measures.
+  #buffer_size: 100000
+
+  # The number of measures to insert in a single query.
+  #batch_size: 10000
+
+##
+## SQLite/PostgreSQL db that is used to store metadata such us metric names, dashboards, alerts,
+## and so on.
+##
+db:
+  # Either sqlite or postgres.
+  driver: sqlite
+  # Database connection string.
+  #
+  # Uptrace automatically creates SQLite database file in the current working directory.
+  # Make sure the directory is writable by Uptrace process.
+  dsn: "file:uptrace.sqlite3?_pragma=foreign_keys(1)&_pragma=busy_timeout(1000)"
+
+# Secret key that is used to sign JWT tokens etc.
+secret_key: 102c1a557c314fc28198acd017960843
+
+# Enable to log HTTP requests and database queries.
+debug: false