Examples with ZooKeeperCacheListener org.apache.pulsar.zookeeper.ZooKeeperCacheListener used on opensource projects

Example 1 with ZooKeeperCacheListener

use of org.apache.pulsar.zookeeper.ZooKeeperCacheListener in project incubator-pulsar by apache.

the class BrokerService method updateDynamicServiceConfiguration.

/**
 * Updates pulsar.ServiceConfiguration's dynamic field with value persent into zk-dynamic path. It also validates
 * dynamic-value before updating it and throws {@code IllegalArgumentException} if validation fails
 */
private void updateDynamicServiceConfiguration() {
    Optional<Map<String, String>> configCache = Optional.empty();
    try {
        // create dynamic-config znode if not present
        if (pulsar.getZkClient().exists(BROKER_SERVICE_CONFIGURATION_PATH, false) == null) {
            try {
                byte[] data = ObjectMapperFactory.getThreadLocal().writeValueAsBytes(Maps.newHashMap());
                ZkUtils.createFullPathOptimistic(pulsar.getZkClient(), BROKER_SERVICE_CONFIGURATION_PATH, data, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            } catch (KeeperException.NodeExistsException e) {
            // Ok
            }
        }
        configCache = dynamicConfigurationCache.get(BROKER_SERVICE_CONFIGURATION_PATH);
    } catch (Exception e) {
        log.warn("Failed to read zookeeper path [{}]:", BROKER_SERVICE_CONFIGURATION_PATH, e);
    }
    if (configCache.isPresent()) {
        configCache.get().forEach((key, value) -> {
            // validate field
            if (dynamicConfigurationMap.containsKey(key) && dynamicConfigurationMap.get(key).validator != null) {
                if (!dynamicConfigurationMap.get(key).validator.test(value)) {
                    log.error("Failed to validate dynamic config {} with value {}", key, value);
                    throw new IllegalArgumentException(String.format("Failed to validate dynamic-config %s/%s", key, value));
                }
            }
            // update field value
            try {
                Field field = ServiceConfiguration.class.getDeclaredField(key);
                if (field != null && field.isAnnotationPresent(FieldContext.class)) {
                    field.setAccessible(true);
                    field.set(pulsar().getConfiguration(), FieldParser.value(value, field));
                    log.info("Successfully updated {}/{}", key, value);
                }
            } catch (Exception e) {
                log.warn("Failed to update service configuration {}/{}, {}", key, value, e.getMessage());
            }
        });
    }
    // register a listener: it updates field value and triggers appropriate registered field-listener only if
    // field's value has been changed so, registered doesn't have to update field value in ServiceConfiguration
    dynamicConfigurationCache.registerListener(new ZooKeeperCacheListener<Map<String, String>>() {

        @SuppressWarnings("unchecked")
        @Override
        public void onUpdate(String path, Map<String, String> data, Stat stat) {
            if (BROKER_SERVICE_CONFIGURATION_PATH.equalsIgnoreCase(path) && data != null) {
                data.forEach((configKey, value) -> {
                    Field configField = dynamicConfigurationMap.get(configKey).field;
                    Object newValue = FieldParser.value(data.get(configKey), configField);
                    if (configField != null) {
                        Consumer listener = configRegisteredListeners.get(configKey);
                        try {
                            Object existingValue = configField.get(pulsar.getConfiguration());
                            configField.set(pulsar.getConfiguration(), newValue);
                            log.info("Successfully updated configuration {}/{}", configKey, data.get(configKey));
                            if (listener != null && !existingValue.equals(newValue)) {
                                listener.accept(newValue);
                            }
                        } catch (Exception e) {
                            log.error("Failed to update config {}/{}", configKey, newValue);
                        }
                    } else {
                        log.error("Found non-dynamic field in dynamicConfigMap {}/{}", configKey, newValue);
                    }
                });
            }
        }
    });
}