diff --git a/corvus.conf b/corvus.conf
index 0e919ee..f4edefb 100644
--- a/corvus.conf
+++ b/corvus.conf
@@ -38,6 +38,15 @@ syslog 0
 #
 # statsd localhost:8125
 # metric_interval 10
+#
+# Slowlog:
+# Send slow command to statsd. The `slow_threshold` is in microseconds,
+# every command whose lantency exceeds `slow_threshold` will be sent.
+# Note that the lantency here is the time spent in proxy,
+# including redirection caused by MOVED and ASK.
+# Set it to negative value to disable slow log.
+#
+# slow_threshold 1000
 
 # Buffer size allocated each time avoiding fregments
 # Buffer used in processing data recieving or sending
diff --git a/src/command.c b/src/command.c
index 04e140c..3f54beb 100644
--- a/src/command.c
+++ b/src/command.c
@@ -36,13 +36,6 @@ enum {
     CMD_EXTRA,
 };
 
-struct cmd_item {
-    char *cmd;
-    int value;
-    int type;
-    int access;
-};
-
 const char *rep_err = "-ERR Proxy error\r\n";
 const char *rep_parse_err = "-ERR Proxy fail to parse command\r\n";
 const char *rep_forward_err = "-ERR Proxy fail to forward command\r\n";
@@ -61,7 +54,8 @@ static const char *rep_noauth = "-NOAUTH Authentication required.\r\n";
 static const char *rep_auth_err = "-ERR invalid password\r\n";
 static const char *rep_auth_not_set = "-ERR Client sent AUTH, but no password is set\r\n";
 
-static struct cmd_item cmds[] = {CMD_DO(CMD_BUILD_MAP)};
+struct cmd_item cmds[] = {CMD_DO(CMD_BUILD_MAP)};
+const size_t CMD_NUM = sizeof(cmds) / sizeof(struct cmd_item);
 static struct dict command_map;
 
 static inline uint8_t *cmd_get_data(struct mbuf *b, struct buf_ptr ptr[], int *len)
@@ -933,6 +927,10 @@ void cmd_stats(struct command *cmd, int64_t end_time)
     ATOMIC_INC(ctx->stats.total_latency, latency);
     ATOMIC_SET(ctx->last_command_latency, latency);
 
+    if (config.slow_threshold >= 0 && latency > config.slow_threshold * 1000) {
+        ATOMIC_INC(cmd->server->info->slow_cmd_counts[cmd->cmd_type], 1);
+    }
+
     if (!STAILQ_EMPTY(&cmd->sub_cmds)) {
         first = STAILQ_FIRST(&cmd->sub_cmds);
         last = STAILQ_LAST(&cmd->sub_cmds, command, sub_cmd_next);
diff --git a/src/command.h b/src/command.h
index 264989b..de1fcd9 100644
--- a/src/command.h
+++ b/src/command.h
@@ -231,6 +231,13 @@ struct redirect_info {
     int type;
 };
 
+struct cmd_item {
+    char *cmd;
+    int value;
+    int type;
+    int access;
+};
+
 /* error responses */
 const char *rep_err,
       *rep_parse_err,
diff --git a/src/connection.c b/src/connection.c
index 581ff2f..94bcb4e 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -75,6 +75,8 @@ static struct connection *conn_create_server(struct context *ctx,
     struct connection *server = server_create(ctx, fd);
     struct conn_info *info = server->info;
     memcpy(&info->addr, addr, sizeof(info->addr));
+    extern const size_t CMD_NUM;
+    info->slow_cmd_counts = cv_calloc(CMD_NUM, sizeof(uint32_t));
 
     if (conn_connect(server) == CORVUS_ERR) {
         LOG(ERROR, "conn_create_server: fail to connect %s:%d",
@@ -102,6 +104,7 @@ void conn_info_init(struct conn_info *info)
     info->readonly = false;
     info->readonly_sent = false;
     info->quit = false;
+    info->slow_cmd_counts = NULL;
 
     memset(&info->addr, 0, sizeof(info->addr));
     memset(info->dsn, 0, sizeof(info->dsn));
diff --git a/src/connection.h b/src/connection.h
index e1b4a26..bf15560 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -69,6 +69,9 @@ struct conn_info {
     long long completed_commands;
 
     int8_t status;
+
+    // slow log, only for server connection in worker thread
+    uint32_t *slow_cmd_counts;
 };
 
 TAILQ_HEAD(conn_tqh, connection);
diff --git a/src/corvus.c b/src/corvus.c
index 34c4f69..3e13363 100644
--- a/src/corvus.c
+++ b/src/corvus.c
@@ -38,6 +38,7 @@ void config_init()
     config.bufsize = DEFAULT_BUFSIZE;
     config.requirepass = NULL;
     config.readslave = config.readmasterslave = false;
+    config.slow_threshold = -1;
 
     memset(config.statsd_addr, 0, sizeof(config.statsd_addr));
     config.metric_interval = 10;
@@ -147,6 +148,8 @@ int config_add(char *name, char *value)
             config.node.len++;
             p = strtok(NULL, ",");
         }
+    } else if (strcmp(name, "slow_threshold") == 0) {
+        config.slow_threshold = atoi(value);
     }
     return 0;
 }
@@ -341,6 +344,7 @@ void context_free(struct context *ctx)
         cmd_iov_free(&conn->info->iov);
         conn_free(conn);
         conn_buf_free(conn);
+        cv_free(conn->info->slow_cmd_counts);
         cv_free(conn->info);
         cv_free(conn);
     }
diff --git a/src/corvus.h b/src/corvus.h
index f7e96bc..180dd94 100644
--- a/src/corvus.h
+++ b/src/corvus.h
@@ -104,6 +104,7 @@ struct {
     int64_t client_timeout;
     int64_t server_timeout;
     int bufsize;
+    int64_t slow_threshold;
 } config;
 
 int64_t get_time();
diff --git a/src/stats.c b/src/stats.c
index d69593a..dd63e1f 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -8,6 +8,7 @@
 #include "socket.h"
 #include "logging.h"
 #include "slot.h"
+#include "alloc.h"
 
 #define HOST_LEN 255
 
@@ -33,6 +34,19 @@ static struct {
     double user;
 } used_cpu;
 
+static struct dict slow_counts; // node dsn => slow cmd counts
+
+
+static void stats_free_slow_counts()
+{
+    struct dict_iter iter = DICT_ITER_INITIALIZER;
+    DICT_FOREACH(&slow_counts, &iter) {
+        cv_free(iter.value);
+    }
+
+    dict_free(&slow_counts);
+}
+
 static inline void stats_get_cpu_usage(struct stats *stats)
 {
     struct rusage ru;
@@ -177,7 +191,7 @@ void stats_send_node_info()
 {
     struct bytes *value;
 
-    /* redis-node.127-0-0-1:8000.bytes.{send,recv} */
+    /* redis-node.127-0-0-1-8000.bytes.{send,recv} */
     int len = HOST_LEN + 64;
     char name[len];
 
@@ -216,6 +230,85 @@ void stats_get(struct stats *stats)
     }
 }
 
+static void stats_send_slow_log()
+{
+    if (config.slow_threshold < 0)
+        return;
+
+    const char *fmt = "redis-node.%s.slow_query.%s";
+    const char *sum_fmt = "slow_query.%s";
+    extern struct cmd_item cmds[];
+    extern const size_t CMD_NUM;
+
+    struct connection *server;
+    struct context *contexts = get_contexts();
+
+    {
+        struct dict_iter iter = DICT_ITER_INITIALIZER;
+        DICT_FOREACH(&slow_counts, &iter) {
+            memset(iter.value, 0, CMD_NUM * sizeof(uint32_t));
+        }
+    }
+
+    uint32_t counts_sum[CMD_NUM];
+    memset(counts_sum, 0, sizeof(counts_sum));
+
+    for (size_t i = 0; i < config.thread; i++) {
+        TAILQ_FOREACH(server, &contexts[i].servers, next) {
+            const char *dsn = server->info->dsn;
+            uint32_t *node_counts = NULL;
+            for (size_t j = 0; j < CMD_NUM; j++) {
+                uint32_t count = ATOMIC_IGET(server->info->slow_cmd_counts[j], 0);
+                if (count == 0) continue;
+
+                if (!node_counts) {
+                    node_counts = (uint32_t*)dict_get(&slow_counts, dsn);
+                    if (!node_counts) {
+                        node_counts = cv_calloc(CMD_NUM, sizeof(uint32_t));
+                        dict_set(&slow_counts, dsn, node_counts);
+                    }
+                }
+                node_counts[j] += count;
+                counts_sum[j] += count;
+            }
+        }
+    }
+
+    struct dict_iter iter = DICT_ITER_INITIALIZER;
+    DICT_FOREACH(&slow_counts, &iter) {
+        const char *dsn = iter.key;
+        uint32_t *counts = (uint32_t*)iter.value;
+
+        char addr[ADDRESS_LEN] = {0};
+        strncpy(addr, dsn, ADDRESS_LEN);
+        for (size_t i = 0; i < ADDRESS_LEN; i++) {
+            if (addr[i] == '.' || addr[i] == ':')
+                addr[i] = '-';
+        }
+
+        for (size_t i = 0; i < CMD_NUM; i++) {
+            if(counts[i] == 0) continue;
+
+            const char *cmd = cmds[i].cmd;
+            int n = snprintf(NULL, 0, fmt, addr, cmd);
+            char buf[n + 1];
+            snprintf(buf, sizeof(buf), fmt, addr, cmd);
+            stats_send(buf, counts[i]);
+        }
+    }
+
+    for (size_t i = 0; i < CMD_NUM; i++) {
+        uint32_t sum = counts_sum[i];
+        if (sum) {
+            const char *cmd = cmds[i].cmd;
+            int n = snprintf(NULL, 0, sum_fmt, cmd);
+            char buf[n + 1];
+            snprintf(buf, sizeof(buf), sum_fmt, cmd);
+            stats_send(buf, sum);
+        }
+    }
+}
+
 void *stats_daemon(void *data)
 {
     /* Make the thread killable at any time can work reliably. */
@@ -226,6 +319,7 @@ void *stats_daemon(void *data)
         sleep(config.metric_interval);
         stats_send_simple();
         stats_send_node_info();
+        stats_send_slow_log();
         LOG(DEBUG, "sending metrics");
     }
     return NULL;
@@ -250,6 +344,8 @@ int stats_init()
         if (hostname[i] == '.') hostname[i] = '-';
     }
 
+    dict_init(&slow_counts);
+
     LOG(INFO, "starting stats thread");
     return thread_spawn(&stats_ctx, stats_daemon);
 }
@@ -259,6 +355,7 @@ void stats_kill()
     int err;
 
     dict_free(&bytes_map);
+    stats_free_slow_counts();
 
     if (pthread_cancel(stats_ctx.thread) == 0) {
         if ((err = pthread_join(stats_ctx.thread, NULL)) != 0) {