Last night, when the live broadcast to the climax of the sudden screen card into the PPT, the pop-up screen was instantly "anchor with a landline live? The screen, I really wanted to go along with the network line to the operator room to Yang. These days to do live, not by DDoS avalanche are embarrassed to say that they are engaged in the Internet, but more disgusting than being attacked - you spend money to buy a high-defense CDN, the result is that the audience was stuck in their own collective performances transient.
On the market blowing sky-high high defense services, nine out of ten even real traffic impact can not be carried. Some manufacturers of "high defense" node is simply a second-hand cell phone room transformation, attack traffic over 10G directly lying flat, but also some latency nominal 50ms actually run 200ms +, the audience has long been changing the station, you are still there to feed feed feed test microphone it.
I take their platform daily average of 3 million online real business as a mouse, 30 consecutive days rotated five mainstream service providers, test data may offend people but must tell the truth:Latency below 80ms is true - live CDN, to resist the attack below 800Gbps is only a basic operation, the critical moment can let you live than the news broadcasts are still stable to be considered reliable!。
First give the conclusion of the lazy bagCDN5's comprehensive resistance is best suited for live game broadcasting, CDN07's cross-country lines are friendly to overseas miking, and 08Host's cost-effectiveness allows small platforms to take a breather. However, if your family anchor every day by the peer 'special care', it is recommended to look directly at the end of the article of the magic program.
Why is live CDN ten times more expensive than ordinary acceleration services? First of all, the traffic is sudden - the king of the group battle when the audience data request volume can soar 400%, followed by real-time requirements, video transmission delay of more than 100ms will appear audio and video mismatch, not to mention those who specialize in picking PK time period to start the directional attack.
The first pit of the actual test came from a vendor that advertises "1Tbps ultra-high defense". The attack test did carry 600G of SYN Flood, but the live push stream suddenly stuck to the code rate diving. Packet capture found that their cleaning strategy is too violent, the normal video stream is also treated as abnormal traffic to limit the speed. The technical customer service actually suggested that I "lower the code rate of the push stream to adapt to the protection strategy", and I tore up the annual fee order on the spot.
Now sharing the real-world data (all tests based on the same gigabit bandwidth, push-stream 1080p60 fps environment):
CDN5The delay of Beijing node is 67ms, Guangzhou node is 72ms, and Los Angeles node is 158ms. 650Gbps mixed attacks were successfully defended in the anti-attack test, and the delay fluctuation during the period is only 13ms. the disadvantage is that the price of overseas nodes is comparable to the leased line, but the middle and eastern regions of the country are stable like an old dog.
CDN07Japan and Singapore node latency antithetical, respectively, only 89ms and 101ms. especially suitable for Southeast Asia audience more show live, CC attack ability of the strongest of the five, but can not carry the flooding attack on the super traffic, encountered more than 800G directly triggered a black hole for 30 minutes.
08Host: the price is only the industry average price of 60%, latency performance moderate (domestic nodes 85-110ms), but intelligent scheduling to do amazing - automatic scheduling of the Pearl River Delta users to the Hong Kong node, the Northeast iron cut to the Seoul node, with cross-border lines to counteract domestic congestion, this wave of operation is worth a drink of two cups.
The remaining two platforms that do not mention names, one in the evening peak latency soared to 380ms still hard to say that it is the operator's problem, the other is even more desperate - after the attack directly back to me to the default server, the original IP almost naked on the Internet. Sincerely suggest that these vendors to sell sweet potatoes, do not come to the scourge of the live industry.
High-defense CDN just look at the publicity parameters absolutely stepped on mine, have to stare at the three core details:Intelligence of BGP line quality, cleaning cluster deployment location, and source back policyThe "global node" of many vendors is actually a rented single-line server room. Many vendors' "global nodes" are in fact leased single-line server rooms, and cross-border transmission detours are farther than the Silk Road.
Share a tearful lesson: last year, a platform to buy nodes to send high defense, the results of the attack came directly to me cut to the U.S. machine room, the domestic audience all around the Pacific Ocean sightseeing. Now before signing the contract must let customer service to provide routing tracking map, dare to have "202.97.."Direct passes for congested segment nodes of such backbone networks.
What saves lives in practice is often the detailed configuration. For example, after turning on the "live mode" in the CDN5 background, you need to manually adjust the TCP window size and UDP retransmission policy:
Don't look at just milliseconds of parameter adjustment, the evening peak hours can reduce the 40% of lag and reconnection. In addition, be sure to turn off the CDN vendor's "intelligent compression" function - video streams after the second compression of the bit rate fault, the picture is so muddled that even the anchor eyelids can not be seen.
Don't believe in the myth of "unlimited protection" when it comes to DDoS resistance. The actual test found a claim of unlimited protection vendors, hit 1.2Tbps directly to the whole staff lost packets 90%. real scenarios below 300Gbps attack accounted for 95%, so the choice to focus on the cleaning accuracy of the 100-500G range, rather than the blind pursuit of astronomical figures.
Teach you a trick: ask the vendor to provide cleaning report samples, focusing on the False Positive rate (False Kill Rate). I've seen the most outrageous can be 30% normal users as an attack intercept, a little better can be controlled at 0.5% below. In addition, it must be confirmed that whether to provide 24-hour manual escort, the middle of the night was hit when the robot customer service than the audience slipped faster.
Now for the price catnip. A platform's basic package of 1999 RMB/month seems cheap, but 'excess traffic' is billed at 15 RMB/G. An anchor jumped ship and gave me a 3700 RMB bill that night. Now only choose unlimited traffic package, although the unit price is high, but sleep solid.
Finally dump a king bomb program - with multi-cloud disaster recovery stacked cost down 40%. 08Host to carry the daily traffic, CDN5 as a standby node, encountered a large flow of attacks through the DNS second cut. The key point of configuration is that the TTL must be pressed to within 30 seconds:
Other manufacturers may scold me when they know this trick, but it really allows you to realize the protection of $500,000 with a $200,000 budget. The actual switching process is senseless for the audience, and even the pop-ups don't break.
Summarize the storm theory:The essence of high-defense CDN is to bet on the probability - betting that the attack will not exceed the cleaning capacity, betting that the line will not be suddenly congested, betting that the vendor's technical brother did not fall asleep!. So either you buy the top services to lie flat and let them slaughter you, or you use technical solutions to spread the risk. I'll share how to use WebRTC seconds traditional CDN when I finish testing the new edge computing solution next month.
Before leaving to say a big truth: now about 70% live lag is not a bandwidth problem at all, but the SSL certificate configuration error, DNS query timeout these tart operation. Check your TLS version is not still parked in 1.1, Node.js server keep-alive timeout settings is not more than 3 seconds - change these better than the replacement of the CDN useful ten times.
(Test data as of May 2024, the manufacturer's formula changes every month, remember to catch the package first)
