Status: Not Connected

I use PhpRedis (v4.3.0) but when i enable Redis Object Cache status display not connected

Here diagnostic log:

Status: Not Connected
Redis Version: Unknown
Client: PhpRedis (v4.3.0)
Drop-in: Valid
Connection Exception: php_network_getaddresses: getaddrinfo failed: Name or service not known (RedisException)
Redis Extension: 4.3.0
Predis Client: 1.1.1
PHP Version: 7.2.17
Multisite: No
Global Prefix: "wp_"
Blog Prefix: "wp_"
WP_REDIS_HOST: "redis"
WP_REDIS_MAXTTL: "14400"
WP_CACHE_KEY_SALT: "example.com_obj:"
Global Groups: [
    "blog-details",
    "blog-id-cache",
    "blog-lookup",
    "global-posts",
    "networks",
    "rss",
    "sites",
    "site-details",
    "site-lookup",
    "site-options",
    "site-transient",
    "users",
    "useremail",
    "userlogins",
    "usermeta",
    "user_meta",
    "userslugs"
]
Ignored Groups: [
    "counts",
    "plugins",
    "blog-details",
    "blog-id-cache",
    "blog-lookup",
    "global-posts",
    "networks",
    "rss",
    "sites",
    "site-details",
    "site-lookup",
    "site-options",
    "site-transient",
    "users",
    "useremail",
    "userlogins",
    "usermeta",
    "user_meta",
    "userslugs",
    "blog_meta",
    "themes"
]