redis启动报错详解（2）Unrecoverable error: corrupted cluster config file.

在https://blog.csdn.net/zly_9117/article/details/83349778这篇博文的基础上，进行redis启动时发现了另外一个错误，错误内容如下

➜  7000 ../redis-server redis.conf &
[1] 11045
11045:C 24 Oct 2018 19:26:52.320 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
11045:C 24 Oct 2018 19:26:52.320 # Redis version=999.999.999, bits=64, commit=54e8dd11, modified=0, pid=11045, just started
11045:C 24 Oct 2018 19:26:52.320 # Configuration loaded
11045:M 24 Oct 2018 19:26:52.322 * Increased maximum number of open files to 10032 (it was originally set to 7168).
11045:M 24 Oct 2018 19:26:52.323 # Unrecoverable error: corrupted cluster config file.

从字面意思理解是损坏的cluster配置，同样到源码中查找相应的错误抛出点找到如下信息

1.错误日志的输出点是下边的这段代码

fmterr:
    serverLog(LL_WARNING,
        "Unrecoverable error: corrupted cluster config file.");
    zfree(line);
    if (fp) fclose(fp);
    exit(1);
}

根据源码解读发现，我们没有建立nodes.conf文件，默认此方法会返回一个C_ERR，然后由调用方clusterInit函数新建此文件并建立cluster，clusterLoadConfig函数整体代码如下。但是现在找到了此文件，并进行解读时报错，证明redis.conf配置文件中配置的内容有误。查找配置文件发现cluster-config-file参数配置错误，改成cluster-config-file nodes.conf问题解决。

/* Load the cluster config from 'filename'.
 *
 * If the file does not exist or is zero-length (this may happen because
 * when we lock the nodes.conf file, we create a zero-length one for the
 * sake of locking if it does not already exist), C_ERR is returned.
 * If the configuration was loaded from the file, C_OK is returned. */
int clusterLoadConfig(char *filename) {
    FILE *fp = fopen(filename,"r");
    struct stat sb;
    char *line;
    int maxline, j;

    if (fp == NULL) {
        if (errno == ENOENT) {
            return C_ERR;
        } else {
            serverLog(LL_WARNING,
                "Loading the cluster node config from %s: %s",
                filename, strerror(errno));
            exit(1);
        }
    }

    /* Check if the file is zero-length: if so return C_ERR to signal
     * we have to write the config. */
    if (fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
        fclose(fp);
        return C_ERR;
    }

    /* Parse the file. Note that single lines of the cluster config file can
     * be really long as they include all the hash slots of the node.
     * This means in the worst possible case, half of the Redis slots will be
     * present in a single line, possibly in importing or migrating state, so
     * together with the node ID of the sender/receiver.
     *
     * To simplify we allocate 1024+CLUSTER_SLOTS*128 bytes per line. */
    maxline = 1024+CLUSTER_SLOTS*128;
    line = zmalloc(maxline);
    while(fgets(line,maxline,fp) != NULL) {
        int argc;
        sds *argv;
        clusterNode *n, *master;
        char *p, *s;

        /* Skip blank lines, they can be created either by users manually
         * editing nodes.conf or by the config writing process if stopped
         * before the truncate() call. */
        if (line[0] == '\n' || line[0] == '\0') continue;

        /* Split the line into arguments for processing. */
        argv = sdssplitargs(line,&argc);
        if (argv == NULL) goto fmterr;

        /* Handle the special "vars" line. Don't pretend it is the last
         * line even if it actually is when generated by Redis. */
        if (strcasecmp(argv[0],"vars") == 0) {
            for (j = 1; j < argc; j += 2) {
                if (strcasecmp(argv[j],"currentEpoch") == 0) {
                    server.cluster->currentEpoch =
                            strtoull(argv[j+1],NULL,10);
                } else if (strcasecmp(argv[j],"lastVoteEpoch") == 0) {
                    server.cluster->lastVoteEpoch =
                            strtoull(argv[j+1],NULL,10);
                } else {
                    serverLog(LL_WARNING,
                        "Skipping unknown cluster config variable '%s'",
                        argv[j]);
                }
            }
            sdsfreesplitres(argv,argc);
            continue;
        }

        /* Regular config lines have at least eight fields */
        if (argc < 8) goto fmterr;

        /* Create this node if it does not exist */
        n = clusterLookupNode(argv[0]);
        if (!n) {
            n = createClusterNode(argv[0],0);
            clusterAddNode(n);
        }
        /* Address and port */
        if ((p = strrchr(argv[1],':')) == NULL) goto fmterr;
        *p = '\0';
        memcpy(n->ip,argv[1],strlen(argv[1])+1);
        char *port = p+1;
        char *busp = strchr(port,'@');
        if (busp) {
            *busp = '\0';
            busp++;
        }
        n->port = atoi(port);
        /* In older versions of nodes.conf the "@busport" part is missing.
         * In this case we set it to the default offset of 10000 from the
         * base port. */
        n->cport = busp ? atoi(busp) : n->port + CLUSTER_PORT_INCR;

        /* Parse flags */
        p = s = argv[2];
        while(p) {
            p = strchr(s,',');
            if (p) *p = '\0';
            if (!strcasecmp(s,"myself")) {
                serverAssert(server.cluster->myself == NULL);
                myself = server.cluster->myself = n;
                n->flags |= CLUSTER_NODE_MYSELF;
            } else if (!strcasecmp(s,"master")) {
                n->flags |= CLUSTER_NODE_MASTER;
            } else if (!strcasecmp(s,"slave")) {
                n->flags |= CLUSTER_NODE_SLAVE;
            } else if (!strcasecmp(s,"fail?")) {
                n->flags |= CLUSTER_NODE_PFAIL;
            } else if (!strcasecmp(s,"fail")) {
                n->flags |= CLUSTER_NODE_FAIL;
                n->fail_time = mstime();
            } else if (!strcasecmp(s,"handshake")) {
                n->flags |= CLUSTER_NODE_HANDSHAKE;
            } else if (!strcasecmp(s,"noaddr")) {
                n->flags |= CLUSTER_NODE_NOADDR;
            } else if (!strcasecmp(s,"nofailover")) {
                n->flags |= CLUSTER_NODE_NOFAILOVER;
            } else if (!strcasecmp(s,"noflags")) {
                /* nothing to do */
            } else {
                serverPanic("Unknown flag in redis cluster config file");
            }
            if (p) s = p+1;
        }

        /* Get master if any. Set the master and populate master's
         * slave list. */
        if (argv[3][0] != '-') {
            master = clusterLookupNode(argv[3]);
            if (!master) {
                master = createClusterNode(argv[3],0);
                clusterAddNode(master);
            }
            n->slaveof = master;
            clusterNodeAddSlave(master,n);
        }

        /* Set ping sent / pong received timestamps */
        if (atoi(argv[4])) n->ping_sent = mstime();
        if (atoi(argv[5])) n->pong_received = mstime();

        /* Set configEpoch for this node. */
        n->configEpoch = strtoull(argv[6],NULL,10);

        /* Populate hash slots served by this instance. */
        for (j = 8; j < argc; j++) {
            int start, stop;

            if (argv[j][0] == '[') {
                /* Here we handle migrating / importing slots */
                int slot;
                char direction;
                clusterNode *cn;

                p = strchr(argv[j],'-');
                serverAssert(p != NULL);
                *p = '\0';
                direction = p[1]; /* Either '>' or '<' */
                slot = atoi(argv[j]+1);
                if (slot < 0 || slot >= CLUSTER_SLOTS) goto fmterr;
                p += 3;
                cn = clusterLookupNode(p);
                if (!cn) {
                    cn = createClusterNode(p,0);
                    clusterAddNode(cn);
                }
                if (direction == '>') {
                    server.cluster->migrating_slots_to[slot] = cn;
                } else {
                    server.cluster->importing_slots_from[slot] = cn;
                }
                continue;
            } else if ((p = strchr(argv[j],'-')) != NULL) {
                *p = '\0';
                start = atoi(argv[j]);
                stop = atoi(p+1);
            } else {
                start = stop = atoi(argv[j]);
            }
            if (start < 0 || start >= CLUSTER_SLOTS) goto fmterr;
            if (stop < 0 || stop >= CLUSTER_SLOTS) goto fmterr;
            while(start <= stop) clusterAddSlot(n, start++);
        }

        sdsfreesplitres(argv,argc);
    }
    /* Config sanity check */
    if (server.cluster->myself == NULL) goto fmterr;

    zfree(line);
    fclose(fp);

    serverLog(LL_NOTICE,"Node configuration loaded, I'm %.40s", myself->name);

    /* Something that should never happen: currentEpoch smaller than
     * the max epoch found in the nodes configuration. However we handle this
     * as some form of protection against manual editing of critical files. */
    if (clusterGetMaxEpoch() > server.cluster->currentEpoch) {
        server.cluster->currentEpoch = clusterGetMaxEpoch();
    }
    return C_OK;

fmterr:
    serverLog(LL_WARNING,
        "Unrecoverable error: corrupted cluster config file.");
    zfree(line);
    if (fp) fclose(fp);
    exit(1);
}