monasca.persister.repository.cassandra.CassandraAlarmRepo.java Source code

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Here is the source code for monasca.persister.repository.cassandra.CassandraAlarmRepo.java

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/*
 * Copyright (c) 2017 SUSE LLC
 *
 * 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
 *
 *    http://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.
 */

package monasca.persister.repository.cassandra;

import java.security.NoSuchAlgorithmException;
import java.sql.SQLException;
import java.sql.Timestamp;

import javax.inject.Inject;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;

import io.dropwizard.setup.Environment;
import monasca.common.model.event.AlarmStateTransitionedEvent;
import monasca.persister.configuration.PersisterConfig;
import monasca.persister.repository.Repo;
import monasca.persister.repository.RepoException;

/**
 * This class is not thread safe.
 *
 */
public class CassandraAlarmRepo extends CassandraRepo implements Repo<AlarmStateTransitionedEvent> {

    private static final Logger logger = LoggerFactory.getLogger(CassandraAlarmRepo.class);

    private static String EMPTY_REASON_DATA = "{}";

    private static final int MAX_BYTES_PER_CHAR = 4;
    private static final int MAX_LENGTH_VARCHAR = 65000;

    private int retention;

    private ObjectMapper objectMapper = new ObjectMapper();

    @Inject
    public CassandraAlarmRepo(CassandraCluster cluster, PersisterConfig config, Environment environment)
            throws NoSuchAlgorithmException, SQLException {
        super(cluster, environment, config.getCassandraDbConfiguration().getMaxWriteRetries(),
                config.getAlarmHistoryConfiguration().getBatchSize());

        this.retention = config.getCassandraDbConfiguration().getRetentionPolicy() * 24 * 3600;

        logger.debug("Instantiating " + this.getClass().getName());

        this.objectMapper
                .setPropertyNamingStrategy(PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);

        session = cluster.getAlarmsSession();

        logger.debug(this.getClass().getName() + " is fully instantiated");

    }

    public void addToBatch(AlarmStateTransitionedEvent message, String id) {

        String metricsString = getSerializedString(message.metrics, id);

        // Validate metricsString does not exceed a sufficient maximum upper bound
        if (metricsString.length() * MAX_BYTES_PER_CHAR >= MAX_LENGTH_VARCHAR) {
            metricsString = "[]";
            logger.warn("length of metricsString for alarm ID {} exceeds max length of {}", message.alarmId,
                    MAX_LENGTH_VARCHAR);
        }

        String subAlarmsString = getSerializedString(message.subAlarms, id);

        if (subAlarmsString.length() * MAX_BYTES_PER_CHAR >= MAX_LENGTH_VARCHAR) {
            subAlarmsString = "[]";
            logger.warn("length of subAlarmsString for alarm ID {} exceeds max length of {}", message.alarmId,
                    MAX_LENGTH_VARCHAR);
        }

        queue.offerLast(cluster.getAlarmHistoryInsertStmt().bind(retention, metricsString, message.oldState.name(),
                message.newState.name(), subAlarmsString, message.stateChangeReason, EMPTY_REASON_DATA,
                message.tenantId, message.alarmId, new Timestamp(message.timestamp)));
    }

    private String getSerializedString(Object o, String id) {

        try {
            return this.objectMapper.writeValueAsString(o);
        } catch (JsonProcessingException e) {
            logger.error("[[}]: failed to serialize object {}", id, o, e);
            return "";
        }
    }

    @Override
    public int flush(String id) throws RepoException {
        return handleFlush(id);
    }
}