update keydb.conf with new configs from redis unstable

* added replping command for initiating replication

* backwards compatibility for replping (retry if not recognized)

* don't allow ping during loading (load balancer fix)

* changed replping warning to notice

keydb.conf

@@ -32,8 +32,17 @@
 # If instead you are interested in using includes to override configuration
 # options, it is better to use include as the last line.
 #
+# Included paths may contain wildcards. All files matching the wildcards will
+# be included in alphabetical order.
+# Note that if an include path contains a wildcards but no files match it when
+# the server is started, the include statement will be ignored and no error will
+# be emitted.  It is safe, therefore, to include wildcard files from empty
+# directories.
+#
 # include /path/to/local.conf
 # include /path/to/other.conf
+# include /path/to/fragments/*.conf
+#
 
 ################################## MODULES #####################################
 
@@ -49,23 +58,32 @@
 # for connections from all available network interfaces on the host machine.
 # It is possible to listen to just one or multiple selected interfaces using
 # the "bind" configuration directive, followed by one or more IP addresses.
+# Each address can be prefixed by "-", which means that redis will not fail to
+# start if the address is not available. Being not available only refers to
+# addresses that does not correspond to any network interfece. Addresses that
+# are already in use will always fail, and unsupported protocols will always BE
+# silently skipped.
 #
 # Examples:
 #
-# bind 192.168.1.100 10.0.0.1
-# bind 127.0.0.1 ::1
+# bind 192.168.1.100 10.0.0.1     # listens on two specific IPv4 addresses
+# bind 127.0.0.1 ::1              # listens on loopback IPv4 and IPv6
+# bind * -::*                     # like the default, all available interfaces
 #
 # ~~~ WARNING ~~~ If the computer running KeyDB is directly exposed to the
 # internet, binding to all the interfaces is dangerous and will expose the
 # instance to everybody on the internet. So by default we uncomment the
 # following bind directive, that will force KeyDB to listen only on the
-# IPv4 loopback interface address (this means KeyDB will only be able to
+# IPv4 and IPv6 (if available) loopback interface addresses (this means KeyDB will only be able to
 # accept client connections from the same host that it is running on).
 #
 # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
 # JUST COMMENT OUT THE FOLLOWING LINE.
+#
+# You will also need to set a password unless you explicitly disable protected
+# mode.
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-bind 127.0.0.1
+bind 127.0.0.1 -::1
 
 # Protected mode is a layer of security protection, in order to avoid that
 # KeyDB instances left open on the internet are accessed and exploited.
@@ -125,7 +143,7 @@ timeout 0
 # On other kernels the period depends on the kernel configuration.
 #
 # A reasonable value for this option is 300 seconds, which is the new
-# KeyDB default starting with Redis 3.2.1.
+# KeyDB default starting with KeyDB 3.2.1.
 tcp-keepalive 300
 
 ################################# TLS/SSL #####################################
@@ -143,13 +161,35 @@ tcp-keepalive 300
 #
 # tls-cert-file keydb.crt 
 # tls-key-file keydb.key
+#
+# If the key file is encrypted using a passphrase, it can be included here
+# as well.
+#
+# tls-key-file-pass secret
+
+# Normally KeyDB uses the same certificate for both server functions (accepting
+# connections) and client functions (replicating from a master, establishing
+# cluster bus connections, etc.).
+#
+# Sometimes certificates are issued with attributes that designate them as
+# client-only or server-only certificates. In that case it may be desired to use
+# different certificates for incoming (server) and outgoing (client)
+# connections. To do that, use the following directives:
+#
+# tls-client-cert-file client.crt
+# tls-client-key-file client.key
+#
+# If the key file is encrypted using a passphrase, it can be included here
+# as well.
+#
+# tls-client-key-file-pass secret
 
 # Configure a DH parameters file to enable Diffie-Hellman (DH) key exchange:
 #
 # tls-dh-params-file keydb.dh
 
 # Configure a CA certificate(s) bundle or directory to authenticate TLS/SSL
-# clients and peers.  Redis requires an explicit configuration of at least one
+# clients and peers. KeyDB requires an explicit configuration of at least one
 # of these, and will not implicitly use the system wide configuration.
 #
 # tls-ca-cert-file ca.crt
@@ -172,7 +212,7 @@ tcp-keepalive 300
 #
 # tls-replication yes
 
-# By default, the Redis Cluster bus uses a plain TCP connection. To enable
+# By default, the KeyDB Cluster bus uses a plain TCP connection. To enable
 # TLS for the bus protocol, use the following directive:
 #
 # tls-cluster yes
@@ -269,6 +309,16 @@ logfile ""
 # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
 # syslog-facility local0
 
+# To disable the built in crash log, which will possibly produce cleaner core
+# dumps when they are needed, uncomment the following:
+#
+# crash-log-enabled no
+
+# To disable the fast memory check that's run as part of the crash log, which
+# will possibly let keydb terminate sooner, uncomment the following:
+#
+# crash-memcheck-enabled no
+
 # Set the number of databases. The default database is DB 0, you can select
 # a different one on a per-connection basis using SELECT <dbid> where
 # dbid is a number between 0 and 'databases'-1
@@ -282,9 +332,31 @@ databases 16
 # ASCII art logo in startup logs by setting the following option to yes.
 always-show-logo yes
 
+# By default, KeyDB modifies the process title (as seen in 'top' and 'ps') to
+# provide some runtime information. It is possible to disable this and leave
+# the process name as executed by setting the following to no.
+set-proc-title yes
+
 # Retrieving "message of today" using CURL requests.
 #enable-motd yes
 
+# When changing the process title, KeyDB uses the following template to construct
+# the modified title.
+#
+# Template variables are specified in curly brackets. The following variables are
+# supported:
+#
+# {title}           Name of process as executed if parent, or type of child process.
+# {listen-addr}     Bind address or '*' followed by TCP or TLS port listening on, or
+#                   Unix socket if only that's available.
+# {server-mode}     Special mode, i.e. "[sentinel]" or "[cluster]".
+# {port}            TCP port listening on, or 0.
+# {tls-port}        TLS port listening on, or 0.
+# {unixsocket}      Unix domain socket listening on, or "".
+# {config-file}     Name of configuration file used.
+#
+proc-title-template "{title} {listen-addr} {server-mode}"
+
 ################################ SNAPSHOTTING  ################################
 #
 # Save the DB on disk:
@@ -299,8 +371,6 @@ always-show-logo yes
 #   after 300 sec (5 min) if at least 10 keys changed
 #   after 60 sec if at least 10000 keys changed
 #
-#   Note: you can disable saving completely by commenting out all "save" lines.
-#
 #   It is also possible to remove all the previously configured save
 #   points by adding a save directive with a single empty string argument
 #   like in the following example:
@@ -341,6 +411,21 @@ rdbcompression yes
 # tell the loading code to skip the check.
 rdbchecksum yes
 
+# Enables or disables full sanitation checks for ziplist and listpack etc when
+# loading an RDB or RESTORE payload. This reduces the chances of a assertion or
+# crash later on while processing commands.
+# Options:
+#   no         - Never perform full sanitation
+#   yes        - Always perform full sanitation
+#   clients    - Perform full sanitation only for user connections.
+#                Excludes: RDB files, RESTORE commands received from the master
+#                connection, and client connections which have the
+#                skip-sanitize-payload ACL flag.
+# The default should be 'clients' but since it currently affects cluster
+# resharding via MIGRATE, it is temporarily set to 'no' by default.
+#
+# sanitize-dump-payload no
+
 # The filename where to dump the DB
 dbfilename dump.rdb
 
@@ -397,7 +482,7 @@ dir ./
 #
 # masterauth <master-password>
 #
-# However this is not enough if you are using KeyDB ACLs (for Redis version
+# However this is not enough if you are using KeyDB ACLs (for KeyDB version
 # 6 or greater), and the default user is not capable of running the PSYNC
 # command and/or other commands needed for replication (gathered in the
 # @replication group). In this case it's better to configure a special user to
@@ -443,7 +528,7 @@ replica-serve-stale-data yes
 # may also cause problems if clients are writing to it because of a
 # misconfiguration.
 #
-# Since Redis 2.6 by default replicas are read-only.
+# Since KeyDB 2.6 by default replicas are read-only.
 #
 # Note: read only replicas are not designed to be exposed to untrusted clients
 # on the internet. It's just a protection layer against misuse of the instance.
@@ -595,6 +680,18 @@ repl-disable-tcp-nodelay no
 # By default the priority is 100.
 replica-priority 100
 
+# -----------------------------------------------------------------------------
+# By default, KeyDB Sentinel includes all replicas in its reports. A replica
+# can be excluded from KeyDB Sentinel's announcements. An unannounced replica
+# will be ignored by the 'sentinel replicas <master>' command and won't be
+# exposed to KeyDB Sentinel's clients.
+#
+# This option does not change the behavior of replica-priority. Even with
+# replica-announced set to 'no', the replica can be promoted to master. To
+# prevent this behavior, set replica-priority to 0.
+#
+# replica-announced yes
+
 # It is possible for a master to stop accepting writes if there are less than
 # N replicas connected, having a lag less or equal than M seconds.
 #
@@ -714,6 +811,8 @@ replica-priority 100
 #  off          Disable the user: it's no longer possible to authenticate
 #               with this user, however the already authenticated connections
 #               will still work.
+#  skip-sanitize-payload    RESTORE dump-payload sanitation is skipped.
+#  sanitize-payload         RESTORE dump-payload is sanitized (default).
 #  +<command>   Allow the execution of that command
 #  -<command>   Disallow the execution of that command
 #  +@<category> Allow the execution of all the commands in such category
@@ -736,6 +835,11 @@ replica-priority 100
 #               It is possible to specify multiple patterns.
 #  allkeys      Alias for ~*
 #  resetkeys    Flush the list of allowed keys patterns.
+#  &<pattern>   Add a glob-style pattern of Pub/Sub channels that can be
+#               accessed by the user. It is possible to specify multiple channel
+#               patterns.
+#  allchannels  Alias for &*
+#  resetchannels            Flush the list of allowed channel patterns.
 #  ><password>  Add this password to the list of valid password for the user.
 #               For example >mypass will add "mypass" to the list.
 #               This directive clears the "nopass" flag (see later).
@@ -775,6 +879,40 @@ replica-priority 100
 #
 # Basically ACL rules are processed left-to-right.
 #
+# The following is a list of command categories and their meanings:
+# * keyspace - Writing or reading from keys, databases, or their metadata 
+#     in a type agnostic way. Includes DEL, RESTORE, DUMP, RENAME, EXISTS, DBSIZE,
+#     KEYS, EXPIRE, TTL, FLUSHALL, etc. Commands that may modify the keyspace,
+#     key or metadata will also have `write` category. Commands that only read
+#     the keyspace, key or metadata will have the `read` category.
+# * read - Reading from keys (values or metadata). Note that commands that don't
+#     interact with keys, will not have either `read` or `write`.
+# * write - Writing to keys (values or metadata)
+# * admin - Administrative commands. Normal applications will never need to use
+#     these. Includes REPLICAOF, CONFIG, DEBUG, SAVE, MONITOR, ACL, SHUTDOWN, etc.
+# * dangerous - Potentially dangerous (each should be considered with care for
+#     various reasons). This includes FLUSHALL, MIGRATE, RESTORE, SORT, KEYS,
+#     CLIENT, DEBUG, INFO, CONFIG, SAVE, REPLICAOF, etc.
+# * connection - Commands affecting the connection or other connections.
+#     This includes AUTH, SELECT, COMMAND, CLIENT, ECHO, PING, etc.
+# * blocking - Potentially blocking the connection until released by another
+#     command.
+# * fast - Fast O(1) commands. May loop on the number of arguments, but not the
+#     number of elements in the key.
+# * slow - All commands that are not Fast.
+# * pubsub - PUBLISH / SUBSCRIBE related
+# * transaction - WATCH / MULTI / EXEC related commands.
+# * scripting - Scripting related.
+# * set - Data type: sets related.
+# * sortedset - Data type: zsets related.
+# * list - Data type: lists related.
+# * hash - Data type: hashes related.
+# * string - Data type: strings related.
+# * bitmap - Data type: bitmaps related.
+# * hyperloglog - Data type: hyperloglog related.
+# * geo - Data type: geo related.
+# * stream - Data type: streams related.
+#
 # For more information about ACL configuration please refer to
 # the Redis web site at https://redis.io/topics/acl
 
@@ -798,14 +936,38 @@ acllog-max-len 128
 #
 # aclfile /etc/keydb/users.acl
 
-# IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatibility
+# IMPORTANT NOTE: starting with KeyDB 6 "requirepass" is just a compatibility
 # layer on top of the new ACL system. The option effect will be just setting
 # the password for the default user. Clients will still authenticate using
 # AUTH <password> as usually, or more explicitly with AUTH default <password>
 # if they follow the new protocol: both will work.
 #
+# The requirepass is not compatible with aclfile option and the ACL LOAD
+# command, these will cause requirepass to be ignored.
+#
 # requirepass foobared
 
+# New users are initialized with restrictive permissions by default, via the
+# equivalent of this ACL rule 'off resetkeys -@all'. Starting with KeyDB 6.2, it
+# is possible to manage access to Pub/Sub channels with ACL rules as well. The
+# default Pub/Sub channels permission if new users is controlled by the
+# acl-pubsub-default configuration directive, which accepts one of these values:
+#
+# allchannels: grants access to all Pub/Sub channels
+# resetchannels: revokes access to all Pub/Sub channels
+#
+# To ensure backward compatibility while upgrading KeyDB 6.0, acl-pubsub-default
+# defaults to the 'allchannels' permission.
+#
+# Future compatibility note: it is very likely that in a future version of KeyDB
+# the directive's default of 'allchannels' will be changed to 'resetchannels' in
+# order to provide better out-of-the-box Pub/Sub security. Therefore, it is
+# recommended that you explicitly define Pub/Sub permissions for all users
+# rather then rely on implicit default values. Once you've set explicit
+# Pub/Sub for all existing users, you should uncomment the following line.
+#
+# acl-pubsub-default resetchannels
+
 # Command renaming (DEPRECATED).
 #
 # ------------------------------------------------------------------------
@@ -842,7 +1004,7 @@ acllog-max-len 128
 # Once the limit is reached KeyDB will close all the new connections sending
 # an error 'max number of clients reached'.
 #
-# IMPORTANT: When Redis Cluster is used, the max number of connections is also
+# IMPORTANT: When KeyDB Cluster is used, the max number of connections is also
 # shared with the cluster bus: every node in the cluster will use two
 # connections, one incoming and another outgoing. It is important to size the
 # limit accordingly in case of very large clusters.
@@ -918,7 +1080,15 @@ acllog-max-len 128
 #
 # maxmemory-samples 5
 
-# Starting from Redis 5, by default a replica will ignore its maxmemory setting
+# Eviction processing is designed to function well with the default setting.
+# If there is an unusually large amount of write traffic, this value may need to
+# be increased.  Decreasing this value may reduce latency at the risk of
+# eviction processing effectiveness
+#   0 = minimum latency, 10 = default, 100 = process without regard to latency
+#
+# maxmemory-eviction-tenacity 10
+
+# Starting from KeyDB 5, by default a replica will ignore its maxmemory setting
 # (unless it is promoted to master after a failover or manually). It means
 # that the eviction of keys will be just handled by the master, sending the
 # DEL commands to the replica as keys evict in the master side.
@@ -1011,6 +1181,13 @@ replica-lazy-flush no
 
 lazyfree-lazy-user-del no
 
+# FLUSHDB, FLUSHALL, and SCRIPT FLUSH support both asynchronous and synchronous
+# deletion, which can be controlled by passing the [SYNC|ASYNC] flags into the
+# commands. When neither flag is passed, this directive will be used to determine
+# if the data should be deleted asynchronously.
+
+lazyfree-lazy-user-flush no
+
 ############################ KERNEL OOM CONTROL ##############################
 
 # On Linux, it is possible to hint the kernel OOM killer on what processes
@@ -1042,6 +1219,19 @@ oom-score-adj no
 # oom-score-adj-values to positive values will always succeed.
 oom-score-adj-values 0 200 800
 
+
+#################### KERNEL transparent hugepage CONTROL ######################
+
+# Usually the kernel Transparent Huge Pages control is set to "madvise" or
+# or "never" by default (/sys/kernel/mm/transparent_hugepage/enabled), in which
+# case this config has no effect. On systems in which it is set to "always",
+# KeyDB will attempt to disable it specifically for the KeyDB process in order
+# to avoid latency problems specifically with fork(2) and CoW.
+# If for some reason you prefer to keep it enabled, you can set this config to
+# "no" and the kernel global to "always".
+
+disable-thp yes
+
 ############################## APPEND ONLY MODE ###############################
 
 # By default KeyDB asynchronously dumps the dataset on disk. This mode is
@@ -1269,12 +1459,21 @@ lua-time-limit 5000
 # master in your cluster.
 #
 # Default is 1 (replicas migrate only if their masters remain with at least
-# one replica). To disable migration just set it to a very large value.
+# one replica). To disable migration just set it to a very large value or
+# set cluster-allow-replica-migration to 'no'.
 # A value of 0 can be set but is useful only for debugging and dangerous
 # in production.
 #
 # cluster-migration-barrier 1
 
+# Turning off this option allows to use less automatic cluster configuration.
+# It both disables migration to orphaned masters and migration from masters
+# that became empty.
+#
+# Default is 'yes' (allow automatic migrations).
+#
+# cluster-allow-replica-migration yes
+
 # By default KeyDB Cluster nodes stop accepting queries if they detect there
 # is at least a hash slot uncovered (no available node is serving it).
 # This way if the cluster is partially down (for example a range of hash slots
@@ -1325,17 +1524,23 @@ lua-time-limit 5000
 #
 # In order to make KeyDB Cluster working in such environments, a static
 # configuration where each node knows its public address is needed. The
-# following two options are used for this scope, and are:
+# following four options are used for this scope, and are:
 #
 # * cluster-announce-ip
 # * cluster-announce-port
+# * cluster-announce-tls-port
 # * cluster-announce-bus-port
 #
-# Each instructs the node about its address, client port, and cluster message
+# Each instructs the node about its address, client ports (for connections
+# without and with TLS), and cluster message
 # bus port. The information is then published in the header of the bus packets
 # so that other nodes will be able to correctly map the address of the node
 # publishing the information.
 #
+# If cluster-tls is set to yes and cluster-announce-tls-port is omitted or set
+# to zero, then cluster-announce-port refers to the TLS port. Note also that
+# cluster-announce-tls-port has no effect if cluster-tls is set to no.
+#
 # If the above options are not used, the normal KeyDB Cluster auto-detection
 # will be used instead.
 #
@@ -1347,7 +1552,8 @@ lua-time-limit 5000
 # Example:
 #
 # cluster-announce-ip 10.1.1.5
-# cluster-announce-port 6379
+# cluster-announce-tls-port 6379
+# cluster-announce-port 0
 # cluster-announce-bus-port 6380
 
 ################################## SLOW LOG ###################################
@@ -1421,8 +1627,9 @@ latency-monitor-threshold 0
 #  x     Expired events (events generated every time a key expires)
 #  e     Evicted events (events generated when a key is evicted for maxmemory)
 #  t     Stream commands
+#  d     Module key type events
 #  m     Key-miss events (Note: It is not included in the 'A' class)
-#  A     Alias for g$lshzxet, so that the "AKE" string means all the events
+#  A     Alias for g$lshzxetd, so that the "AKE" string means all the events
 #        (Except key-miss events which are excluded from 'A' due to their
 #         unique nature).
 #

src/Makefile

@@ -127,7 +127,7 @@ ifneq ($(uname_S),Darwin)
 endif
 # Linux ARM32 needs -latomic at linking time
 ifneq (,$(findstring armv,$(uname_M)))
-        FINAL_LIBS+=-latomic
+	FINAL_LIBS+=-latomic
 endif
 
 
@@ -177,7 +177,7 @@ ifeq ($(uname_S),OpenBSD)
 	    FINAL_CXXFLAGS+= -DUSE_BACKTRACE -I/usr/local/include
 	    FINAL_LDFLAGS+= -L/usr/local/lib
 	    FINAL_LIBS+= -lexecinfo
-    	endif
+	endif
 
 else
 ifeq ($(uname_S),NetBSD)
@@ -187,7 +187,7 @@ ifeq ($(uname_S),NetBSD)
 	    FINAL_CFLAGS+= -DUSE_BACKTRACE -I/usr/pkg/include
 	    FINAL_LDFLAGS+= -L/usr/pkg/lib
 	    FINAL_LIBS+= -lexecinfo
-    	endif
+	endif
 else
 ifeq ($(uname_S),FreeBSD)
 	# FreeBSD
@@ -316,6 +316,14 @@ else
     endef
 endif
 
+# Alpine OS doesn't have support for the execinfo backtrace library we use for debug, so we provide an alternate implementation using libwunwind.
+OS := $(shell cat /etc/os-release | grep ID= | head -n 1 | cut -d'=' -f2)
+ifeq ($(OS),alpine)
+    FINAL_CXXFLAGS+=-DUNW_LOCAL_ONLY
+    FINAL_LIBS += -lunwind
+endif
+
+
 REDIS_CC=$(QUIET_CC)$(CC) $(FINAL_CFLAGS)
 REDIS_CXX=$(QUIET_CC)$(CXX) $(FINAL_CXXFLAGS)
 KEYDB_AS=$(QUIET_CC) as --64 -g

src/debug.cpp

@@ -51,6 +51,12 @@ typedef ucontext_t sigcontext_t;
 #include <cxxabi.h>
 #endif /* HAVE_BACKTRACE */
 
+//UNW_LOCAL_ONLY being set means we use libunwind for backtraces instead of execinfo
+#ifdef UNW_LOCAL_ONLY
+#include <libunwind.h>
+#include <cxxabi.h>
+#endif
+
 #ifdef __CYGWIN__
 #ifndef SA_ONSTACK
 #define SA_ONSTACK 0x08000000
@@ -947,7 +953,7 @@ void _serverAssert(const char *estr, const char *file, int line) {
     serverLog(LL_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
 
     if (g_pserver->crashlog_enabled) {
-#ifdef HAVE_BACKTRACE
+#if defined HAVE_BACKTRACE || defined UNW_LOCAL_ONLY
         logStackTrace(NULL, 1);
 #endif
         printCrashReport();
@@ -1044,7 +1050,7 @@ void _serverPanic(const char *file, int line, const char *msg, ...) {
     serverLog(LL_WARNING,"Guru Meditation: %s #%s:%d",fmtmsg,file,line);
 
     if (g_pserver->crashlog_enabled) {
-#ifdef HAVE_BACKTRACE
+#if defined HAVE_BACKTRACE || defined UNW_LOCAL_ONLY
         logStackTrace(NULL, 1);
 #endif
         printCrashReport();
@@ -1599,6 +1605,65 @@ void safe_write(int fd, const void *pv, ssize_t cb)
     } while (offset < cb);
 }
 
+#ifdef UNW_LOCAL_ONLY
+
+/* Logs the stack trace using the libunwind call.
+ * The eip argument is unused as libunwind only gets local context.
+ * The uplevel argument indicates how many of the calling functions to skip.
+ */
+void logStackTrace(void * eip, int uplevel) {
+    (void)eip;//UNUSED
+    const char *msg;
+    int fd = openDirectLogFiledes();
+
+    if (fd == -1) return; /* If we can't log there is anything to do. */
+
+    msg = "\n------ STACK TRACE ------\n";
+    if (write(fd,msg,strlen(msg)) == -1) {/* Avoid warning. */};
+    unw_cursor_t cursor;
+    unw_context_t context;
+
+    unw_getcontext(&context);
+    unw_init_local(&cursor, &context);
+
+    /* Write symbols to log file */
+    msg = "\nBacktrace:\n";
+    if (write(fd,msg,strlen(msg)) == -1) {/* Avoid warning. */};
+
+    for (int i = 0; i < uplevel; i++) {
+        unw_step(&cursor);
+    }
+
+    while ( unw_step(&cursor) ) {
+    unw_word_t ip, sp, off;
+
+    unw_get_reg(&cursor, UNW_REG_IP, &ip);
+    unw_get_reg(&cursor, UNW_REG_SP, &sp);
+
+    char symbol[256] = {"<unknown>"};
+    char *name = symbol;
+
+    if ( !unw_get_proc_name(&cursor, symbol, sizeof(symbol), &off) ) {
+        int status;
+        if ( (name = abi::__cxa_demangle(symbol, NULL, NULL, &status)) == 0 )
+        name = symbol;
+    }
+
+    dprintf(fd, "%s(+0x%" PRIxPTR ") [0x%016" PRIxPTR "] sp=0x%016" PRIxPTR "\n",
+        name,
+        static_cast<uintptr_t>(off),
+        static_cast<uintptr_t>(ip),
+        static_cast<uintptr_t>(sp));
+
+    if ( name != symbol )
+        free(name);
+    }
+}
+
+#endif /* UNW_LOCAL_ONLY */
+
+#ifdef HAVE_BACKTRACE
+
 void backtrace_symbols_demangle_fd(void **trace, size_t csym, int fd)
 {
     char **syms = backtrace_symbols(trace, csym);
@@ -1642,8 +1707,6 @@ void backtrace_symbols_demangle_fd(void **trace, size_t csym, int fd)
     free(syms);
 }
 
-#ifdef HAVE_BACKTRACE
-
 /* Logs the stack trace using the backtrace() call. This function is designed
  * to be called from signal handlers safely.
  * The eip argument is optional (can take NULL).
@@ -1934,6 +1997,9 @@ void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
 
     logRegisters(uc);
 #endif
+#ifdef UNW_LOCAL_ONLY
+    logStackTrace(NULL, 1);
+#endif 
 
     printCrashReport();
 
@@ -2028,6 +2094,8 @@ void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
     serverLogFromHandler(LL_WARNING,"\n--- WATCHDOG TIMER EXPIRED ---");
 #ifdef HAVE_BACKTRACE
     logStackTrace(getMcontextEip(uc), 1);
+#elif defined UNW_LOCAL_ONLY
+    logStackTrace(NULL, 1);
 #else
     serverLogFromHandler(LL_WARNING,"Sorry: no support for backtrace().");
 #endif

src/replication.cpp

@@ -2759,18 +2759,19 @@ void syncWithMaster(connection *conn) {
         goto error;
     }
 
+retry_connect:
     /* Send a PING to check the master is able to reply without errors. */
-    if (mi->repl_state == REPL_STATE_CONNECTING) {
+    if (mi->repl_state == REPL_STATE_CONNECTING || mi->repl_state == REPL_STATE_RETRY_NOREPLPING) {
         serverLog(LL_NOTICE,"Non blocking connect for SYNC fired the event.");
         /* Delete the writable event so that the readable event remains
          * registered and we can wait for the PONG reply. */
         connSetReadHandler(conn, syncWithMaster);
         connSetWriteHandler(conn, NULL);
-        mi->repl_state = REPL_STATE_RECEIVE_PING_REPLY;
         /* Send the PING, don't check for errors at all, we have the timeout
          * that will take care about this. */
-        err = sendCommand(conn,"PING",NULL);
+        err = sendCommand(conn,mi->repl_state == REPL_STATE_RETRY_NOREPLPING ? "PING" : "REPLPING",NULL);
         if (err) goto write_error;
+        mi->repl_state = REPL_STATE_RECEIVE_PING_REPLY;
         return;
     }
 
@@ -2783,7 +2784,13 @@ void syncWithMaster(connection *conn) {
          * Note that older versions of Redis replied with "operation not
          * permitted" instead of using a proper error code, so we test
          * both. */
-        if (err[0] != '+' &&
+        if (strncmp(err,"-ERR unknown command",20) == 0) {
+            serverLog(LL_NOTICE,"Master does not support REPLPING, sending PING instead...");
+            mi->repl_state = REPL_STATE_RETRY_NOREPLPING;
+            sdsfree(err);
+            err = NULL;
+            goto retry_connect;
+        } else if (err[0] != '+' &&
             strncmp(err,"-NOAUTH",7) != 0 &&
             strncmp(err,"-NOPERM",7) != 0 &&
             strncmp(err,"-ERR operation not permitted",28) != 0)

src/server.cpp

@@ -753,6 +753,10 @@ struct redisCommand redisCommandTable[] = {
      "ok-stale ok-loading fast @connection @replication",
      0,NULL,0,0,0,0,0,0},
 
+     {"replping",pingCommand,-1,
+     "ok-stale fast @connection @replication",
+     0,NULL,0,0,0,0,0,0},
+
     {"echo",echoCommand,2,
      "fast @connection",
      0,NULL,0,0,0,0,0,0},
@@ -2768,6 +2772,7 @@ void createSharedObjects(void) {
     shared.lastid = makeObjectShared("LASTID",6);
     shared.default_username = makeObjectShared("default",7);
     shared.ping = makeObjectShared("ping",4);
+    shared.replping = makeObjectShared("replping", 8);
     shared.setid = makeObjectShared("SETID",5);
     shared.keepttl = makeObjectShared("KEEPTTL",7);
     shared.load = makeObjectShared("LOAD",4);

src/server.h

@@ -505,6 +505,7 @@ typedef enum {
     REPL_STATE_NONE = 0,            /* No active replication */
     REPL_STATE_CONNECT,             /* Must connect to master */
     REPL_STATE_CONNECTING,          /* Connecting to master */
+    REPL_STATE_RETRY_NOREPLPING,    /* Master does not support REPLPING, retry with PING */
     /* --- Handshake states, must be ordered --- */
     REPL_STATE_RECEIVE_PING_REPLY,  /* Wait for PING reply */
     REPL_STATE_SEND_HANDSHAKE,      /* Send handshake sequance to master */
@@ -1283,7 +1284,7 @@ struct sharedObjectsStruct {
     *emptyscan, *multi, *exec, *left, *right, *hset, *srem, *xgroup, *xclaim,  
     *script, *replconf, *eval, *persist, *set, *pexpireat, *pexpire, 
     *time, *pxat, *px, *retrycount, *force, *justid, 
-    *lastid, *ping, *setid, *keepttl, *load, *createconsumer,
+    *lastid, *ping, *replping, *setid, *keepttl, *load, *createconsumer,
     *getack, *special_asterick, *special_equals, *default_username,
     *hdel, *zrem, *mvccrestore, *pexpirememberat,
     *select[PROTO_SHARED_SELECT_CMDS],