diff --git a/tests/runtime/filter_multiline.c b/tests/runtime/filter_multiline.c
index c5d42494930..9b3cfc6fa1e 100644
--- a/tests/runtime/filter_multiline.c
+++ b/tests/runtime/filter_multiline.c
@@ -49,6 +49,78 @@ static int cb_check_result(void *record, size_t size, void *data)
 }
 
 
+pthread_mutex_t result_mutex = PTHREAD_MUTEX_INITIALIZER;
+int num_output = 0;
+static int get_output_num()
+{
+    int ret;
+    pthread_mutex_lock(&result_mutex);
+    ret = num_output;
+    pthread_mutex_unlock(&result_mutex);
+
+    return ret;
+}
+
+static void set_output_num(int num)
+{
+    pthread_mutex_lock(&result_mutex);
+    num_output = num;
+    pthread_mutex_unlock(&result_mutex);
+}
+
+static void clear_output_num()
+{
+    set_output_num(0);
+}
+
+struct str_list {
+    size_t size; /* size of lists */
+    int ignore_min_line_num; /* ignore line if the length is less than this value */
+    char **lists; /* string lists */
+};
+
+/* Callback to check expected results */
+static int cb_check_str_list(void *record, size_t size, void *data)
+{
+    char *p;
+    char *out_line = record;
+    int num = get_output_num();
+    int count = 0;
+    size_t i;
+    struct str_list *l = (struct str_list *)data;
+
+    if (!TEST_CHECK(out_line != NULL)) {
+        TEST_MSG("out_line is NULL");
+        return -1;
+    }
+
+    if (!TEST_CHECK(l != NULL)) {
+        TEST_MSG("l is NULL");
+        flb_free(out_line);
+        return -1;
+    }
+
+    if (strlen(out_line) < l->ignore_min_line_num) {
+        flb_free(out_line);
+        return 0;
+    }
+
+    for (i=0; i<l->size; i++) {
+        p = strstr(out_line, l->lists[i]);
+        if (p != NULL) {
+            count++;
+        }
+    }
+    if(!TEST_CHECK(count != 0)) {
+        TEST_MSG("%s is not matched", out_line);
+    }
+    set_output_num(num+count);
+
+    flb_free(out_line);
+    return 0;
+}
+
+
 
 static struct filter_test *filter_test_create(struct flb_lib_out_cb *data)
 {
@@ -86,7 +158,7 @@ static struct filter_test *filter_test_create(struct flb_lib_out_cb *data)
     o_ffd = flb_output(ctx->flb, (char *) "lib", (void *) data);
     TEST_CHECK(o_ffd >= 0);
     flb_output_set(ctx->flb, o_ffd,
-                   "match", "test",
+                   "match", "test*",
                    "format", "json",
                    NULL);
 
@@ -426,7 +498,196 @@ static void flb_test_multiline_partial_message_concat_two_ids()
     filter_test_destroy(ctx);
 }
 
+
+/*
+ * create 2 in_lib instances and pass multiline
+ * https://github.com/fluent/fluent-bit/issues/5524
+*/
+static void flb_test_ml_buffered_two_streams()
+{
+    struct flb_lib_out_cb cb_data;
+    struct filter_test *ctx;
+    int i_ffd_2;
+    int ret;
+    int i;
+    int bytes;
+    int len;
+    char line_buf[2048] = {0};
+    int line_num;
+    int num;
+
+    char *expected_strs[] = {"Exception in thread main java.lang.IllegalStateException: ..null property\\n     at com.example.myproject.Author.getBookIds(xx.java:38)\\n     at com.example.myproject.Bootstrap.main(Bootstrap.java:14)\\nCaused by: java.lang.NullPointerException\\n     at com.example.myproject.Book.getId(Book.java:22)\\n     at com.example.myproject.Author.getBookIds(Author.java:35)\\n     ... 1 more",
+    "Dec 14 06:41:08 Exception in thread main java.lang.RuntimeException: Something has gone wrong, aborting!\\n    at com.myproject.module.MyProject.badMethod(MyProject.java:22)\\n    at com.myproject.module.MyProject.oneMoreMethod(MyProject.java:18)\\n    at com.myproject.module.MyProject.anotherMethod(MyProject.java:14)\\n    at com.myproject.module.MyProject.someMethod(MyProject.java:10)\\n    at com.myproject.module.MyProject.main(MyProject.java:6)"};
+    struct str_list expected = {
+                                .size = sizeof(expected_strs)/sizeof(char*),
+                                .lists = &expected_strs[0],
+                                .ignore_min_line_num = 64,
+    };
+
+    char *ml_logs_1[] = {"Exception in thread main java.lang.IllegalStateException: ..null property",
+                         "     at com.example.myproject.Author.getBookIds(xx.java:38)",
+                         "     at com.example.myproject.Bootstrap.main(Bootstrap.java:14)",
+                         "Caused by: java.lang.NullPointerException",
+                         "     at com.example.myproject.Book.getId(Book.java:22)",
+                         "     at com.example.myproject.Author.getBookIds(Author.java:35)",
+                         "     ... 1 more",
+                         "single line"};
+    char *ml_logs_2[] = {
+                         "single line...",
+                         "Dec 14 06:41:08 Exception in thread main java.lang.RuntimeException: Something has gone wrong, aborting!",
+                         "    at com.myproject.module.MyProject.badMethod(MyProject.java:22)",
+                         "    at com.myproject.module.MyProject.oneMoreMethod(MyProject.java:18)",
+                         "    at com.myproject.module.MyProject.anotherMethod(MyProject.java:14)",
+                         "    at com.myproject.module.MyProject.someMethod(MyProject.java:10)",
+                         "    at com.myproject.module.MyProject.main(MyProject.java:6)",
+                         "another line..."};
+
+    cb_data.cb = cb_check_str_list;
+    cb_data.data = (void *)&expected;
+
+    clear_output_num();
+
+    TEST_CHECK(sizeof(ml_logs_1)/sizeof(char*) == sizeof(ml_logs_2)/sizeof(char*));
+    line_num = sizeof(ml_logs_1)/sizeof(char*);
+
+    /* Create test context */
+    ctx = filter_test_create((void *) &cb_data);
+    if (!ctx) {
+        exit(EXIT_FAILURE);
+    }
+    i_ffd_2 = flb_input(ctx->flb, (char *) "lib", NULL);
+    TEST_CHECK(i_ffd_2 >= 0);
+    flb_input_set(ctx->flb, i_ffd_2, "tag", "test2", NULL);
+
+    /* Configure filter */
+    ret = flb_filter_set(ctx->flb, ctx->f_ffd,
+                         "multiline.key_content", "log",
+                         "multiline.parser", "java",
+                         "buffer", "on",
+                         "debug_flush", "on",
+                         NULL);
+    TEST_CHECK(ret == 0);
+
+
+    /* Start the engine */
+    ret = flb_start(ctx->flb);
+    TEST_CHECK(ret == 0);
+
+    for (i=0; i<line_num; i++) {
+        sprintf(&line_buf[0], "[%d, {\"log\":\"%s\"}]", i, ml_logs_1[i]);
+        len = strlen(line_buf);
+        bytes = flb_lib_push(ctx->flb, ctx->i_ffd, &line_buf[0], len);
+        TEST_CHECK(bytes == len);
+
+
+        sprintf(&line_buf[0], "[%d, {\"log\":\"%s\"}]", i, ml_logs_2[i]);
+        len = strlen(line_buf);
+        bytes = flb_lib_push(ctx->flb, i_ffd_2, &line_buf[0], len);
+        TEST_CHECK(bytes == len);
+    }
+    sleep(4);
+
+    num = get_output_num();
+    if (!TEST_CHECK(num == 2))  {
+        TEST_MSG("output error. got %d expect 2", num);
+    }
+
+    filter_test_destroy(ctx);
+}
+
+static void flb_test_ml_buffered_16_streams()
+{
+    struct flb_lib_out_cb cb_data;
+    struct filter_test *ctx;
+    int i_ffds[16] = {0};
+    int ffd_num = sizeof(i_ffds)/sizeof(int);
+    int ret;
+    int i;
+    int j;
+    int bytes;
+    int len;
+    char line_buf[2048] = {0};
+    char tag_buf[32] = {0};
+    int line_num;
+    int num;
+
+    char *expected_strs[] = {"Exception in thread main java.lang.IllegalStateException: ..null property\\n     at com.example.myproject.Author.getBookIds(xx.java:38)\\n     at com.example.myproject.Bootstrap.main(Bootstrap.java:14)\\nCaused by: java.lang.NullPointerException\\n     at com.example.myproject.Book.getId(Book.java:22)\\n     at com.example.myproject.Author.getBookIds(Author.java:35)\\n     ... 1 more"};
+
+    struct str_list expected = {
+                                .size = sizeof(expected_strs)/sizeof(char*),
+                                .lists = &expected_strs[0],
+                                .ignore_min_line_num = 64,
+    };
+
+    char *ml_logs[] = {"Exception in thread main java.lang.IllegalStateException: ..null property",
+                       "     at com.example.myproject.Author.getBookIds(xx.java:38)",
+                       "     at com.example.myproject.Bootstrap.main(Bootstrap.java:14)",
+                       "Caused by: java.lang.NullPointerException",
+                       "     at com.example.myproject.Book.getId(Book.java:22)",
+                       "     at com.example.myproject.Author.getBookIds(Author.java:35)",
+                       "     ... 1 more",
+                       "single line"};
+
+    cb_data.cb = cb_check_str_list;
+    cb_data.data = (void *)&expected;
+
+    clear_output_num();
+
+    line_num = sizeof(ml_logs)/sizeof(char*);
+
+    /* Create test context */
+    ctx = filter_test_create((void *) &cb_data);
+    if (!ctx) {
+        exit(EXIT_FAILURE);
+    }
+
+    i_ffds[0] = ctx->i_ffd;
+    for (i=1; i<ffd_num; i++) {
+        i_ffds[i] = flb_input(ctx->flb, (char *) "lib", NULL);
+        TEST_CHECK(i_ffds[i] >= 0);
+        sprintf(&tag_buf[0], "test%d", i);
+        flb_input_set(ctx->flb, i_ffds[i], "tag", tag_buf, NULL);
+    }
+
+    /* Configure filter */
+    ret = flb_filter_set(ctx->flb, ctx->f_ffd,
+                         "multiline.key_content", "log",
+                         "multiline.parser", "java",
+                         "buffer", "on",
+                         "debug_flush", "on",
+                         NULL);
+    TEST_CHECK(ret == 0);
+
+
+    /* Start the engine */
+    ret = flb_start(ctx->flb);
+    TEST_CHECK(ret == 0);
+
+    for (i=0; i<line_num; i++) {
+        sprintf(&line_buf[0], "[%d, {\"log\":\"%s\"}]", i, ml_logs[i]);
+        len = strlen(line_buf);
+        for (j=0; j<ffd_num; j++)  {
+            bytes = flb_lib_push(ctx->flb, i_ffds[j], &line_buf[0], len);
+            TEST_CHECK(bytes == len);
+        }
+    }
+    sleep(4);
+
+    num = get_output_num();
+    if (!TEST_CHECK(num == ffd_num))  {
+        TEST_MSG("output error. got %d expect %d", num, ffd_num);
+    }
+
+    filter_test_destroy(ctx);
+}
+
+
+
+
 TEST_LIST = {
+    {"ml_buffered_two_streams" , flb_test_ml_buffered_two_streams},
+    {"ml_buffered_16_streams" , flb_test_ml_buffered_16_streams},
+
     {"multiline_buffered_one_record"                      , flb_test_multiline_buffered_one_output_record },
     {"multiline_buffered_two_record"                      , flb_test_multiline_buffered_two_output_record },
     {"flb_test_multiline_unbuffered"                      , flb_test_multiline_unbuffered },
@@ -434,4 +695,4 @@ TEST_LIST = {
     {"flb_test_multiline_partial_message_concat"          , flb_test_multiline_partial_message_concat },
     {"flb_test_multiline_partial_message_concat_two_ids"  , flb_test_multiline_partial_message_concat_two_ids },
     {NULL, NULL}
-};
\ No newline at end of file
+};