谷歌云内存商店(Redis),实例刚启动时无法连接到Redis

我解决这个问题的方法如下:简而言之,我添加了ping方法,它试图从Redis设置并获取值;如果可能,则应用程序已准备就绪。

实施:

第一 ,您需要更新app.yaml添加以下内容:

readiness_check:
path: "/readiness_check"
check_interval_sec: 5
timeout_sec: 4
failure_threshold: 2
success_threshold: 2
app_start_timeout_sec: 300

,在rest控制器中:

@GetMapping("/readiness_check")
public ResponseEntity<?> readiness_check() {

    if (!cacheConfig.ping()) {
        return ResponseEntity.notFound().build();
    }

    return ResponseEntity.ok().build();
}

第三 ,类CacheConfig:

public boolean ping() {
    long prefix = System.currentTimeMillis();
    try {
        redisTemplate.opsForValue().set("readiness_check_" + prefix, Boolean.TRUE, 100, TimeUnit.SECONDS);
        Boolean val = (Boolean) redisTemplate.opsForValue().get("readiness_check_" + prefix);
        return Boolean.TRUE.equals(val);
    } catch (Exception e) {
        LOGGER.info("ping failed for " + System.currentTimeMillis());
        return false;
    }
}

附笔。 另外,如果有人需要完全实现CacheConfig:

@Configuration
public class CacheConfig {

    private static final Logger LOGGER = Logger.getLogger(CacheConfig.class.getName());

    @Value("${spring.redis.host}")
    private String redisHost;

    private final RedisTemplate<String, Object> redisTemplate;

    @Autowired
    public CacheConfig(@Lazy RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @Bean
    JedisConnectionFactory jedisConnectionFactory(
            @Autowired JedisPoolConfig poolConfig
    ) {
        // https://cloud.google.com/memorystore/docs/redis/quotas
        RedisStandaloneConfiguration config = new RedisStandaloneConfiguration(redisHost, 6379);

        JedisClientConfiguration clientConfig = JedisClientConfiguration
                .builder()
                .usePooling()
                .poolConfig(poolConfig)
                .build();

        return new JedisConnectionFactory(config, clientConfig);
    }

    @Bean
    public RedisTemplate<String, Object> redisTemplate(
            @Autowired JedisConnectionFactory jedisConnectionFactory
    ) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(jedisConnectionFactory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer(newObjectMapper()));
        return template;
    }

    /**
     * Example: https://github.com/PengliuIBM/pws_demo/blob/1becdca1bc19320c2742504baa1cada3260f8d93/redisData/src/main/java/com/pivotal/wangyu/study/springdataredis/config/RedisConfig.java
     */
    @Bean
    redis.clients.jedis.JedisPoolConfig jedisPoolConfig() {
        final redis.clients.jedis.JedisPoolConfig poolConfig = new redis.clients.jedis.JedisPoolConfig();

        // Maximum active connections to Redis instance
        poolConfig.setMaxTotal(16);
        // Number of connections to Redis that just sit there and do nothing
        poolConfig.setMaxIdle(16);
        // Minimum number of idle connections to Redis - these can be seen as always open and ready to serve
        poolConfig.setMinIdle(8);

        // Tests whether connection is dead when returning a connection to the pool
        poolConfig.setTestOnBorrow(true);
        // Tests whether connection is dead when connection retrieval method is called
        poolConfig.setTestOnReturn(true);
        // Tests whether connections are dead during idle periods
        poolConfig.setTestWhileIdle(true);

        return poolConfig;
    }

    public boolean ping() {
        long prefix = System.currentTimeMillis();
        try {
            redisTemplate.opsForValue().set("readiness_check_" + prefix, Boolean.TRUE, 100, TimeUnit.SECONDS);
            Boolean val = (Boolean) redisTemplate.opsForValue().get("readiness_check_" + prefix);
            return Boolean.TRUE.equals(val);
        } catch (Exception e) {
            LOGGER.info("ping failed for " + System.currentTimeMillis());
            return false;
        }
    }
}